├── 2D Shapes
    ├── 2Ddiagram
    │   ├── activity_main.xml
    │   └── MainActivity.java
    └── 2Ddiagram1
    │   ├── activity_main.xml
    │   └── MainActivity.java
├── Layouts
    ├── Vertical
    │   ├── MainActivity.java
    │   └── activity_main.xml
    └── Horizontal
    │   ├── MainActivity.java
    │   └── activity_main.xml
├── Location Based Services
    ├── activity_main.xml
    ├── MainActivity.java
    └── GPStrace.java
├── Intent
    ├── activity_main2.xml
    ├── MainActivity2.java
    ├── activity_main.xml
    └── MainActivity.java
├── Notification Messages
    ├── activity_main.xml
    └── MainActivity.java
├── Multithreading
    ├── activity_main.xml
    └── MainActivity.java
├── Count vowels
    ├── activity_main.xml
    └── MainActivity.java
├── Email
    ├── MainActivity.java
    └── activity_main.xml
├── Change Font Size and Color
    ├── MainActivity.java.java
    └── activity_main.xml
├── README.md
├── Billing
    ├── MainActivity.java
    └── activity_main.xml
├── ArithmeticCalculator
    ├── activty_main.xml
    └── MainActivity.java
└── Database Connectivity
    ├── activity_main.xml
    └── MainActivity.java


/2D Shapes/2Ddiagram/activity_main.xml:
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1 | <?xml version="1.0" encoding="utf-8"?>
2 | <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
3 |     xmlns:app="http://schemas.android.com/apk/res-auto"
4 |     xmlns:tools="http://schemas.android.com/tools"
5 |     android:layout_width="match_parent"
6 |     android:layout_height="match_parent"
7 |     tools:context=".MainActivity"/>


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/Layouts/Vertical/MainActivity.java:
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 1 | package com.example.vertical;
 2 | 
 3 | import androidx.appcompat.app.AppCompatActivity;
 4 | 
 5 | import android.os.Bundle;
 6 | 
 7 | public class MainActivity extends AppCompatActivity {
 8 | 
 9 |     @Override
10 |     protected void onCreate(Bundle savedInstanceState) {
11 |         super.onCreate(savedInstanceState);
12 |         setContentView(R.layout.activity_main);
13 |     }
14 | }


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/Layouts/Horizontal/MainActivity.java:
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 1 | package com.example.horizontal;
 2 | 
 3 | import androidx.appcompat.app.AppCompatActivity;
 4 | 
 5 | import android.os.Bundle;
 6 | 
 7 | public class MainActivity extends AppCompatActivity {
 8 | 
 9 |     @Override
10 |     protected void onCreate(Bundle savedInstanceState) {
11 |         super.onCreate(savedInstanceState);
12 |         setContentView(R.layout.activity_main);
13 |     }
14 | }


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/Location Based Services/activity_main.xml:
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 1 | <?xml version="1.0" encoding="utf-8"?>
 2 | <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3 |     android:id="@+id/relativeLayout1"
 4 |     android:layout_width="match_parent"
 5 |     android:layout_height="match_parent" >
 6 |     <Button
 7 |         android:id="@+id/show_Location"
 8 |         android:layout_width="wrap_content"
 9 |         android:layout_height="wrap_content"
10 |         android:text="Show_Location"
11 |         android:layout_centerVertical="true"
12 |         android:layout_centerHorizontal="true"
13 |         />
14 | </RelativeLayout>


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/Intent/activity_main2.xml:
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 1 | <?xml version="1.0" encoding="utf-8"?>
 2 | <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3 |     xmlns:app="http://schemas.android.com/apk/res-auto"
 4 |     xmlns:tools="http://schemas.android.com/tools"
 5 |     android:layout_width="match_parent"
 6 |     android:layout_height="match_parent"
 7 |     android:orientation="vertical"
 8 |     android:gravity="center"
 9 |     android:padding="10dp"
10 |     tools:context=".MainActivity2">
11 |     <TextView
12 |         android:id="@+id/resultTv"
13 |         android:textSize="30sp"
14 |         android:textStyle="bold"
15 |         android:layout_width="match_parent"
16 |         android:layout_height="wrap_content" />
17 | </LinearLayout>
18 | 


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/Notification Messages/activity_main.xml:
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 1 | <?xml version="1.0" encoding="utf-8"?>
 2 | <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3 |     xmlns:app="http://schemas.android.com/apk/res-auto"
 4 |     xmlns:tools="http://schemas.android.com/tools"
 5 |     android:layout_width="match_parent"
 6 |     android:layout_height="match_parent"
 7 |     tools:context=".MainActivity">
 8 |     <Button
 9 |         android:layout_width="match_parent"
10 |         android:layout_height="wrap_content"
11 |         android:id="@+id/notify_btn"
12 |         android:text="Get Notify"
13 |         android:textSize="20dp"
14 |         tools:ignore="MissingConstraints" />
15 | </androidx.constraintlayout.widget.ConstraintLayout>
16 | 


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/2D Shapes/2Ddiagram1/activity_main.xml:
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 1 | <?xml version="1.0" encoding="utf-8"?>
 2 | <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3 |     xmlns:app="http://schemas.android.com/apk/res-auto"
 4 |     xmlns:tools="http://schemas.android.com/tools"
 5 |     android:layout_width="match_parent"
 6 |     android:layout_height="match_parent"
 7 |     tools:context=".MainActivity">
 8 | 
 9 |     <TextView
10 |         android:layout_width="wrap_content"
11 |         android:layout_height="wrap_content"
12 |         android:text="Hello World!"
13 |         app:layout_constraintBottom_toBottomOf="parent"
14 |         app:layout_constraintEnd_toEndOf="parent"
15 |         app:layout_constraintStart_toStartOf="parent"
16 |         app:layout_constraintTop_toTopOf="parent" />
17 | 
18 | </androidx.constraintlayout.widget.ConstraintLayout>


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/Multithreading/activity_main.xml:
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 1 | <?xml version="1.0" encoding="utf-8"?>
 2 | <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3 |     android:layout_width="match_parent"
 4 |     android:layout_height="match_parent"
 5 |     android:orientation="vertical"
 6 |     android:id="@+id/info" >
 7 |     <TextView
 8 |         android:layout_width="wrap_content"
 9 |         android:layout_height="wrap_content"
10 |         android:textSize="35dp"
11 |         android:text="Dhanavidhya" />
12 |     <Button
13 |         android:id="@+id/button1"
14 |         android:layout_width="match_parent"
15 |         android:layout_height="wrap_content"
16 |         android:onClick="fetchData"
17 |         android:text="Start MULTITHREAD" />
18 |     <TextView
19 |         android:id="@+id/textView1"
20 |         android:layout_width="wrap_content"
21 |         android:layout_height="wrap_content"
22 |         android:text="Main thread" />
23 | </LinearLayout>


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/Intent/MainActivity2.java:
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 1 | package com.example.fintent;
 2 | 
 3 | 
 4 | import android.content.Intent;
 5 | import android.os.Bundle;
 6 | import android.widget.TextView;
 7 | import androidx.appcompat.app.ActionBar;
 8 | import androidx.appcompat.app.AppCompatActivity;
 9 | 
10 | public class MainActivity2 extends AppCompatActivity {
11 |     @Override
12 |     protected void onCreate(Bundle savedInstanceState) {
13 |         super.onCreate(savedInstanceState);
14 |         setContentView(R.layout.activity_main2);
15 | //actionbar title
16 |         ActionBar actionBar = getSupportActionBar();
17 |         actionBar.setTitle("Second Activity");
18 | //intent to get data
19 |         Intent intent = getIntent();
20 |         String name = intent.getStringExtra("NAME");
21 |         String email = intent.getStringExtra("EMAIL");
22 |         String phone = intent.getStringExtra("PHONE");
23 | //TextView
24 |         TextView mResultTv = findViewById(R.id.resultTv);
25 | //setText
26 |         mResultTv.setText("Name: "+name+"\nEmail: "+email+ "\nPhone: "+phone);
27 |     }
28 | }


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/Count vowels/activity_main.xml:
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 1 | <?xml version="1.0" encoding="utf-8"?>
 2 | <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3 |     xmlns:app="http://schemas.android.com/apk/res-auto"
 4 |     xmlns:tools="http://schemas.android.com/tools"
 5 |     android:layout_width="match_parent"
 6 |     android:layout_height="match_parent"
 7 |     android:orientation="vertical"
 8 |     android:padding="10dp"
 9 |     tools:context=".MainActivity">
10 | 
11 |     <EditText
12 |         android:id="@+id/editText1"
13 |         android:layout_width="match_parent"
14 |         android:layout_height="wrap_content"
15 |         android:layout_alignParentTop="true"
16 |         android:layout_centerHorizontal="true"
17 |         android:layout_marginTop="14dp"
18 |         android:ems="10"
19 |         android:hint="Type a word to Calculate No of Vowels"
20 |         android:inputType="text"
21 |         android:textSize="25dp" />
22 |     <Button
23 |         android:id="@+id/button1"
24 |         android:layout_width="wrap_content"
25 |         android:layout_height="wrap_content"
26 |         android:layout_alignBottom="@+id/editText2"
27 |         android:layout_alignRight="@+id/editText2"
28 |         android:layout_marginRight="46dp"
29 |         android:text="Count" />
30 | </LinearLayout>


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/Location Based Services/MainActivity.java:
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 1 | package com.example.location1;
 2 | import android.app.Activity;
 3 | import android.os.Bundle;
 4 | import android.view.View;
 5 | import android.widget.Button;
 6 | import android.widget.Toast;
 7 | public class MainActivity extends Activity {
 8 |     Button btnShowLocation;
 9 |     GPStrace gps;
10 |     @Override
11 |     public void onCreate(Bundle savedInstanceState) {
12 |         super.onCreate(savedInstanceState);
13 |         setContentView(R.layout.activity_main);
14 |         btnShowLocation=(Button)findViewById(R.id.show_Location);
15 |         btnShowLocation.setOnClickListener(new View.OnClickListener() {
16 |             @Override
17 |             public void onClick(View v) {
18 |                 gps=new GPStrace(MainActivity.this);
19 |                 if(gps.canGetLocation()){
20 |                     double latitude=gps.getLatitude();
21 |                     double longitude=gps.getLongtiude();
22 |                     Toast.makeText(getApplicationContext(),"Dhanavidhya your Location is \nLat:"+latitude+"\nLong:"+longitude, Toast.LENGTH_LONG).show();
23 |                 }
24 |                 else
25 |                 {
26 |                     gps.showSettingAlert();
27 |                 }
28 |             }
29 |         });
30 |     }
31 | }


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/Intent/activity_main.xml:
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 1 | <?xml version="1.0" encoding="utf-8"?>
 2 | <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3 |     xmlns:app="http://schemas.android.com/apk/res-auto"
 4 |     xmlns:tools="http://schemas.android.com/tools"
 5 |     android:layout_width="match_parent"
 6 |     android:layout_height="match_parent"
 7 |     tools:context=".MainActivity"
 8 |     android:orientation="vertical"
 9 |     android:padding="10dp"
10 |     android:gravity="center">
11 |     <EditText
12 |         android:id="@+id/nameEt"
13 |         android:hint="Enter Name"
14 |         android:inputType="text"
15 |         android:layout_width="match_parent"
16 |         android:layout_height="wrap_content" />
17 |     <EditText
18 |         android:id="@+id/emailEt"
19 |         android:hint="Enter Email"
20 |         android:inputType="textEmailAddress"
21 |         android:layout_width="match_parent"
22 |         android:layout_height="wrap_content" />
23 |     <EditText
24 |         android:id="@+id/phoneEt"
25 |         android:hint="Enter Phone"
26 |         android:inputType="phone"
27 |         android:layout_width="match_parent"
28 |         android:layout_height="wrap_content" />
29 |     <Button
30 |         android:id="@+id/saveBtn"
31 |         android:text="Save"
32 |         android:layout_width="wrap_content"
33 |         android:layout_height="wrap_content" />
34 | </LinearLayout>


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/Email/MainActivity.java:
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 1 | package com.example.email;
 2 | import androidx.appcompat.app.AppCompatActivity;
 3 | 
 4 | import android.content.Intent;
 5 | import android.os.Bundle;
 6 | import android.view.View;
 7 | import android.widget.Button;
 8 | import android.widget.EditText;
 9 | 
10 | public class MainActivity extends AppCompatActivity {
11 | 
12 |     EditText to;
13 |     EditText subject;
14 |     EditText msg;
15 |     Button snd;
16 |     @Override
17 |     protected void onCreate(Bundle savedInstanceState) {
18 |         super.onCreate(savedInstanceState);
19 |         setContentView(R.layout.activity_main);
20 |         to=findViewById(R.id.tofield);
21 |         subject=findViewById(R.id.subfield);
22 |         msg=findViewById(R.id.msgfield);
23 |         snd=findViewById(R.id.snd);
24 | 
25 |         snd.setOnClickListener(new View.OnClickListener() {
26 |             @Override
27 |             public void onClick(View v) {
28 |                 String tolst=to.getText().toString();
29 |                 String[] toarr=tolst.split(",");
30 | 
31 |                 String subj=subject.getText().toString();
32 |                 String msgg=msg.getText().toString();
33 | 
34 |                 Intent i=new Intent(Intent.ACTION_SEND);
35 |                 i.putExtra(Intent.EXTRA_EMAIL,toarr);
36 |                 i.putExtra(Intent.EXTRA_SUBJECT,subj);
37 |                 i.putExtra(Intent.EXTRA_TEXT,msgg);
38 | 
39 |                 i.setType("message/rfc822");
40 |                 startActivity(Intent.createChooser(i,"Choose an E-mail Provider"));
41 |             }
42 |         });
43 | 
44 |     }
45 | }


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/Intent/MainActivity.java:
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 1 | package com.example.fintent;
 2 | 
 3 | 
 4 | import android.content.Intent;
 5 | import android.os.Bundle;
 6 | import android.view.View;
 7 | import android.widget.Button;
 8 | import android.widget.EditText;
 9 | import androidx.appcompat.app.ActionBar;
10 | import androidx.appcompat.app.AppCompatActivity;
11 | 
12 | 
13 | public class MainActivity extends AppCompatActivity {
14 |     @Override
15 |     protected void onCreate(Bundle savedInstanceState) {
16 |         super.onCreate(savedInstanceState);
17 |         setContentView(R.layout.activity_main);
18 | //actionbar title
19 |         ActionBar actionBar = getSupportActionBar();
20 |         actionBar.setTitle("First Activity");
21 | //EditText
22 |         final EditText mNameEt = findViewById(R.id.nameEt);
23 |         final EditText mEmailEt = findViewById(R.id.emailEt);
24 |         final EditText mPhoneEt = findViewById(R.id.phoneEt);
25 | //Button
26 |         Button mSaveBtn = findViewById(R.id.saveBtn);
27 | //button click listener
28 |         mSaveBtn.setOnClickListener(new View.OnClickListener() {
29 |             @Override
30 |             public void onClick(View view) {
31 | //get data from edit text
32 |                 String name = mNameEt.getText().toString();
33 |                 String email = mEmailEt.getText().toString();
34 |                 String phone = mPhoneEt.getText().toString();
35 | //activity intent
36 |                 Intent intent = new Intent(MainActivity.this,MainActivity2.class);
37 |                 intent.putExtra("NAME", name);
38 |                 intent.putExtra("EMAIL", email);
39 |                 intent.putExtra("PHONE", phone);
40 |                 startActivity(intent);
41 |             }
42 |         });
43 |     }
44 | }


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/2D Shapes/2Ddiagram1/MainActivity.java:
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 1 | package com.example.a2ddiagram1;
 2 | 
 3 | import androidx.appcompat.app.AppCompatActivity;
 4 | import android.content.Context;
 5 | import android.graphics.Canvas;
 6 | import android.graphics.Color;
 7 | import android.graphics.Paint;
 8 | import android.graphics.Path;
 9 | import android.os.Bundle;
10 | import android.view.View;
11 | public class MainActivity extends AppCompatActivity {
12 |     DemoView demoview;
13 |     Paint paint=new Paint();
14 |     Path path=new Path();
15 |     @Override
16 |     protected void onCreate(Bundle savedInstanceState) {
17 |         super.onCreate(savedInstanceState);
18 |         demoview=new DemoView(this);
19 |         setContentView(demoview);
20 |     }
21 |     private class DemoView extends View{
22 |         public DemoView(Context context){
23 |             super(context);
24 |         }
25 |         protected void onDraw(Canvas canvas){
26 |             super.onDraw(canvas);
27 |             paint.setStyle(Paint.Style.FILL);
28 |             paint.setColor(Color.WHITE);
29 |             canvas.drawPaint(paint);
30 | //circle border
31 |             paint.setAntiAlias(false);
32 |             paint.setColor(Color.BLACK);
33 |             canvas.drawCircle(500,700,410,paint);
34 | //circle
35 |             paint.setAntiAlias(false);
36 |             paint.setColor(Color.YELLOW);
37 |             canvas.drawCircle(500,700,400,paint);
38 | //left eye
39 |             paint.setAntiAlias(false);
40 | 
41 |             paint.setColor(Color.BLACK);
42 |             canvas.drawOval(300,450,400,650,paint);
43 | //right eye
44 |             paint.setAntiAlias(false);
45 |             paint.setColor(Color.BLACK);
46 |             canvas.drawOval(600,450,700,650,paint);
47 | //smile
48 |             paint.setColor(Color.RED);
49 |             canvas.drawArc(300,700,700,900,180,-180,false,paint);
50 |         }
51 |     }
52 | }


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/Notification Messages/MainActivity.java:
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 1 | package com.example.notification;
 2 | import androidx.appcompat.app.AppCompatActivity;
 3 | import android.annotation.SuppressLint;
 4 | import android.os.Bundle;
 5 | import androidx.core.app.NotificationCompat;
 6 | import androidx.core.app.NotificationManagerCompat;
 7 | import android.app.Notification;
 8 | import android.app.NotificationChannel;
 9 | import android.app.NotificationManager;
10 | import android.os.Build;
11 | import android.view.View;
12 | import android.widget.Button;
13 | public class MainActivity extends AppCompatActivity {
14 |     Button notifyBtn;
15 |     @SuppressLint("MissingInflatedId")
16 |     @Override
17 |     protected void onCreate(Bundle savedInstanceState) {
18 |         super.onCreate(savedInstanceState);
19 |         setContentView(R.layout.activity_main);
20 |         notifyBtn = (Button) findViewById(R.id.notify_btn);
21 |         if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.O){
22 |             NotificationChannel channel = new NotificationChannel("My Notification", "My Notification", NotificationManager.IMPORTANCE_DEFAULT);
23 |             NotificationManager manager = getSystemService(NotificationManager.class);
24 |             manager.createNotificationChannel(channel);
25 |         }
26 |         notifyBtn.setOnClickListener(new View.OnClickListener() {
27 |             @SuppressLint("MissingPermission")
28 |             @Override
29 |             public void onClick(View v) {
30 |                 NotificationCompat.Builder builder = new NotificationCompat.Builder(MainActivity.this, "My Notification");
31 |                 builder.setContentTitle("Dhanavidhya C");
32 |                 builder.setContentText("Hello, Notification from Dhanavidhya");
33 |                 builder.setSmallIcon(R.drawable.ic_launcher_background);
34 |                 builder.setAutoCancel(true);
35 |                 NotificationManagerCompat managerCompat = NotificationManagerCompat.from(MainActivity.this);
36 |                 managerCompat.notify(1,builder.build());
37 |             }
38 |         });
39 |     }
40 | }
41 | 


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/Count vowels/MainActivity.java:
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 1 | package com.example.countvowels;
 2 | 
 3 | 
 4 | import android.annotation.SuppressLint;
 5 | import android.app.Activity;
 6 | import android.os.Bundle;
 7 | import android.view.View;
 8 | import android.view.View.OnClickListener;
 9 | import android.widget.Button;
10 | import android.widget.EditText;
11 | import android.widget.Toast;
12 | 
13 | import java.io.FileOutputStream;
14 | public class MainActivity extends Activity implements OnClickListener
15 | {
16 |     EditText content;
17 |     Button count;
18 |     String file_name;
19 | 
20 |     String strContents;
21 | 
22 |     @SuppressLint("MissingInflatedId")
23 |     @Override
24 |     protected void onCreate(Bundle savedInstanceState) {
25 |         super.onCreate(savedInstanceState);
26 |         setContentView(R.layout.activity_main);
27 |         content=(EditText)findViewById(R.id.editText1);
28 |         count=(Button)findViewById(R.id.button1);
29 |         count.setOnClickListener(this);
30 |     }
31 | 
32 |     @SuppressLint("WrongConstant")
33 |     @Override
34 |     public void onClick(View v)
35 |     {
36 |         if(v.getId()==R.id.button1)
37 |         {
38 |             FileOutputStream fos;
39 |             try {
40 |                 strContents = content.getText().toString();
41 | 
42 |             } catch (Exception e) {}
43 |         }
44 |         if(v.getId()==R.id.button1) {
45 |             int count = 0;
46 |             for (int i = 0; i < strContents.length(); i++) {
47 | 
48 |                 switch (strContents.charAt(i)) {
49 |                     case 'a':
50 |                     case 'e':
51 |                     case 'i':
52 |                     case 'o':
53 |                     case 'u':
54 |                     case 'A':
55 |                     case 'E':
56 |                     case 'I':
57 |                     case 'O':
58 |                     case 'U':
59 |                         count++;
60 |                         break;
61 |                 }
62 |             }
63 |             Toast.makeText(getApplicationContext(), "Total Vovels Are : " + count, Toast.LENGTH_LONG).show();
64 |         }
65 |     }}
66 | 


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/Change Font Size and Color/MainActivity.java.java:
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 1 | package com.example.application1;
 2 | 
 3 | import androidx.appcompat.app.AppCompatActivity;
 4 | 
 5 | import android.graphics.Color;
 6 | import android.os.Bundle;
 7 | import android.view.View;
 8 | import android.widget.Button;
 9 | import android.widget.TextView;
10 | 
11 | public class MainActivity extends AppCompatActivity {
12 |     int ch=1;
13 |     float font=30;
14 |     // private Bundle savedInstanceState;
15 | 
16 |     @Override
17 |     protected void onCreate(Bundle savedInstanceState) {
18 |         super.onCreate(savedInstanceState);
19 |         setContentView(R.layout.activity_main);
20 |         final TextView t= (TextView) findViewById(R.id.textview);
21 |         Button b1= (Button) findViewById(R.id.button3);
22 |         b1.setOnClickListener(new View.OnClickListener() {
23 |             @Override
24 |             public void onClick(View v) {
25 |                 t.setTextSize(font);
26 |                 font = font + 5;
27 |                 if (font == 50)
28 |                     font = 30;
29 |             }
30 |         });
31 |         Button b2= (Button) findViewById(R.id.button5);
32 |         b2.setOnClickListener(new View.OnClickListener() {
33 |             @Override
34 |             public void onClick(View v) {
35 |                 switch (ch) {
36 |                     case 1:
37 |                         t.setTextColor(Color.RED);
38 |                         break;
39 |                     case 2:
40 |                         t.setTextColor(Color.GREEN);
41 |                         break;
42 |                     case 3:
43 |                         t.setTextColor(Color.BLUE);
44 |                         break;
45 |                     case 4:
46 |                         t.setTextColor(Color.CYAN);
47 |                         break;
48 |                     case 5:
49 |                         t.setTextColor(Color.LTGRAY);
50 |                         break;
51 |                     case 6:
52 |                         t.setTextColor(Color.MAGENTA);
53 |                         break;
54 |                     default:
55 |                         throw new IllegalStateException("Unexpected value: " + ch);
56 |                 }
57 |                 ch++;
58 |                 if (ch == 7)
59 |                     ch = 1;
60 |             }
61 |         });
62 |     }
63 | }


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/Change Font Size and Color/activity_main.xml:
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 1 | <?xml version="1.0" encoding="utf-8"?>
 2 | <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3 |     xmlns:app="http://schemas.android.com/apk/res-auto"
 4 |     xmlns:tools="http://schemas.android.com/tools"
 5 |     android:layout_width="match_parent"
 6 |     android:layout_height="match_parent"
 7 |     tools:context=".MainActivity">
 8 | 
 9 |     <TextView
10 |         android:id="@+id/textview"
11 |         android:layout_width="153dp"
12 |         android:layout_height="89dp"
13 |         android:fontFamily="sans-serif-black"
14 |         android:text="Dhanavidhya"
15 |         android:textAlignment="center"
16 |         android:textColor="@color/black"
17 |         android:textSize="20sp"
18 |         android:textStyle="bold"
19 |         app:layout_constraintBottom_toTopOf="@+id/button3"
20 |         app:layout_constraintEnd_toEndOf="parent"
21 |         app:layout_constraintHorizontal_bias="0.5"
22 |         app:layout_constraintStart_toStartOf="parent"
23 |         app:layout_constraintTop_toTopOf="parent"
24 |         app:layout_constraintVertical_bias="0.5" />
25 | 
26 |     <Button
27 |         android:id="@+id/button3"
28 |         android:layout_width="317dp"
29 |         android:layout_height="80dp"
30 |         android:text="change font size"
31 |         android:textSize="24sp"
32 |         app:layout_constraintBottom_toTopOf="@+id/button5"
33 |         app:layout_constraintEnd_toEndOf="parent"
34 |         app:layout_constraintHorizontal_bias="0.5"
35 |         app:layout_constraintStart_toStartOf="parent"
36 |         app:layout_constraintTop_toBottomOf="@+id/textview"
37 |         app:layout_constraintVertical_bias="0.5" />
38 | 
39 |     <Button
40 |         android:id="@+id/button5"
41 |         android:layout_width="314dp"
42 |         android:layout_height="85dp"
43 |         android:text="change font color"
44 |         android:textSize="24sp"
45 |         app:layout_constraintBottom_toBottomOf="parent"
46 |         app:layout_constraintEnd_toEndOf="parent"
47 |         app:layout_constraintHorizontal_bias="0.5"
48 |         app:layout_constraintStart_toStartOf="parent"
49 |         app:layout_constraintTop_toBottomOf="@+id/button3"
50 |         app:layout_constraintVertical_bias="0.5" />
51 | 
52 | </androidx.constraintlayout.widget.ConstraintLayout>


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
 1 | # Mobile-Application-Development
 2 | # Change Font Size and Color
 3 | ![WhatsApp Image 2023-07-09 at 1 09 40 PM](https://github.com/Dhanavidhya/Mobile-Application-Development/assets/102801453/4f68701d-1d61-4b12-b08f-7e2e34190bf4)
 4 | # Arithmetic Calculator
 5 | ![WhatsApp Image 2023-07-09 at 1 12 46 PM](https://github.com/Dhanavidhya/Mobile-Application-Development/assets/102801453/a93f098d-483b-4399-ad01-8a7c5365def5)
 6 | # Billing
 7 | ![WhatsApp Image 2023-07-09 at 1 12 46 PM](https://github.com/Dhanavidhya/Mobile-Application-Development/assets/102801453/fcd8ce24-a60e-46fd-b1cc-4bce30e78ebe)
 8 | # Count Vowels
 9 | ![WhatsApp Image 2023-07-09 at 1 15 29 PM](https://github.com/Dhanavidhya/Mobile-Application-Development/assets/102801453/dbc6a1d8-044e-4350-ac51-fb488eee458f)
10 | # Intent
11 | ![WhatsApp Image 2023-07-09 at 1 21 18 PM (1)](https://github.com/Dhanavidhya/Mobile-Application-Development/assets/102801453/502cbcc0-ffca-4fbb-88db-f64ee4c08a43)
12 | # Layouts - Vertical
13 | ![WhatsApp Image 2023-07-09 at 1 25 35 PM](https://github.com/Dhanavidhya/Mobile-Application-Development/assets/102801453/43326a2f-4d6a-448a-8f57-002759e3fb70)
14 | # Layouts - Horizontal
15 | ![WhatsApp Image 2023-07-09 at 1 26 55 PM](https://github.com/Dhanavidhya/Mobile-Application-Development/assets/102801453/e8cca72a-2893-4a87-956e-09572b6d7b95)
16 | # Notification Messages
17 | ![WhatsApp Image 2023-07-09 at 1 33 25 PM](https://github.com/Dhanavidhya/Mobile-Application-Development/assets/102801453/9b6753be-9177-4c48-b4b2-4dbc3f81a584)
18 | # Database Connectivity
19 | <img width="343" alt="db" src="https://github.com/Dhanavidhya/Mobile-Application-Development/assets/102801453/f7ba4987-3f70-416e-8729-a17616db2284">
20 | 
21 | # 2D Shapes
22 | ![WhatsApp Image 2023-07-09 at 1 50 15 PM](https://github.com/Dhanavidhya/Mobile-Application-Development/assets/102801453/62862596-3ce8-44ab-9029-9622f837562a)
23 | # Email
24 | ![WhatsApp Image 2023-07-09 at 1 55 14 PM](https://github.com/Dhanavidhya/Mobile-Application-Development/assets/102801453/3ad32986-9612-46a7-8a05-cfec5dc1e50d)
25 | # Location Based Services
26 | ![WhatsApp Image 2023-07-09 at 1 59 11 PM](https://github.com/Dhanavidhya/Mobile-Application-Development/assets/102801453/1654902d-a91a-4f75-be4f-f9345eccfa99)
27 | # Multithreading
28 | ![WhatsApp Image 2023-07-09 at 2 04 08 PM](https://github.com/Dhanavidhya/Mobile-Application-Development/assets/102801453/27aee530-d4db-4567-8fe4-693339928c5d)
29 | 


--------------------------------------------------------------------------------
/Billing/MainActivity.java:
--------------------------------------------------------------------------------
 1 | package com.example.billing;
 2 | import androidx.appcompat.app.AppCompatActivity;
 3 | 
 4 | import android.os.Bundle;
 5 | import android.view.View;
 6 | import android.widget.Button;
 7 | import android.widget.CheckBox;
 8 | import android.widget.EditText;
 9 | import android.widget.TextView;
10 | 
11 | public class MainActivity extends AppCompatActivity {
12 |     Button submit;
13 |     CheckBox chips, candies, cookies, cakes;
14 |     TextView result;
15 |     EditText numChips, numCookies, numCandies, numCakes;
16 |     @Override
17 |     protected void onCreate(Bundle savedInstanceState) {
18 |         super.onCreate(savedInstanceState);
19 |         setContentView(R.layout.activity_main);
20 |         result = (TextView) findViewById(R.id.result);
21 |         submit = (Button) findViewById(R.id.submit);
22 |         chips = (CheckBox) findViewById(R.id.chips);
23 |         candies = (CheckBox) findViewById(R.id.candy);
24 |         cookies = (CheckBox) findViewById(R.id.cookie);
25 |         cakes = (CheckBox) findViewById(R.id.cakes);
26 |         numCakes = (EditText) findViewById(R.id.numCakes);
27 |         numCandies = (EditText) findViewById(R.id.numCandies);
28 |         numChips = (EditText) findViewById(R.id.numChips);
29 |         numCookies = (EditText) findViewById(R.id.numCookies);
30 |         submit.setOnClickListener(new View.OnClickListener() {
31 |             int total = 0;
32 |             StringBuilder res = new StringBuilder();
33 |             @Override
34 |             public void onClick(View view) {
35 |                 if(chips.isChecked() && numChips.getText().toString() != null){
36 |                     total += 10 * Integer.parseInt(numChips.getText().toString());
37 |                 }
38 |                 if(candies.isChecked() && numCandies.getText().toString() != null){
39 |                     total += 5 * Integer.parseInt(numCandies.getText().toString());
40 |                 }
41 |                 if(cakes.isChecked() && numCakes.getText().toString() != null){
42 |                     total += 50 * Integer.parseInt(numCakes.getText().toString());
43 |                 }
44 |                 if(cookies.isChecked() && numCookies.getText().toString() != null){
45 |                     total += 10 * Integer.parseInt(numCookies.getText().toString());
46 |                 }
47 |                 res.append("Total: "+total+"Rs");
48 |                 result.setText(res.toString());
49 |             }
50 |         });
51 |     }
52 | }


--------------------------------------------------------------------------------
/2D Shapes/2Ddiagram/MainActivity.java:
--------------------------------------------------------------------------------
 1 | package com.example.a2ddiagram;
 2 | 
 3 | import androidx.appcompat.app.AppCompatActivity;
 4 | 
 5 | import android.os.Bundle;
 6 | 
 7 | import android.os.Bundle;
 8 | import android.app.Activity;
 9 | import android.view.Menu;
10 | import android.content.Context;
11 | import android.graphics.Canvas;
12 | import android.graphics.Color;
13 | import android.graphics.Paint;
14 | import android.graphics.Path;
15 | import android.view.View;
16 | 
17 | public class MainActivity extends AppCompatActivity {
18 |     DemoView demoview;
19 |     Paint paint=new Paint();
20 |     Path path = new Path();
21 |     @Override
22 |     protected void onCreate(Bundle savedInstanceState) {
23 |         super.onCreate(savedInstanceState);
24 |         demoview=new DemoView(this);
25 |         setContentView(demoview);
26 |     }
27 |     private class DemoView extends View{
28 |         public DemoView(Context context){
29 | 
30 |             super(context);
31 |         }
32 |         protected void onDraw(Canvas canvas){
33 |             super.onDraw(canvas);
34 | 
35 |             paint.setStyle(Paint.Style.FILL);
36 |             paint.setColor(Color.WHITE);
37 |             canvas.drawPaint(paint);
38 | 
39 |             paint.setAntiAlias(false);
40 |             paint.setColor(Color.RED);
41 |             canvas.drawRect(300, 100, 1000, 500, paint);
42 | 
43 |             paint.setAntiAlias(false);
44 |             paint.setColor(Color.BLUE);
45 |             drawTriangle(canvas, paint, 300, 300, 400);
46 | 
47 |             paint.setAntiAlias(false);
48 |             paint.setColor(Color.GREEN);
49 |             canvas.drawRect(100, 500, 500, 1000, paint);
50 | 
51 |             paint.setColor(Color.MAGENTA);
52 |             canvas.drawCircle(300,750,150,paint);
53 | 
54 |             paint.setAntiAlias(false);
55 |             paint.setColor(Color.YELLOW);
56 |             canvas.drawRect(500, 500, 1000, 1000, paint);
57 | 
58 |         }
59 |         public void drawTriangle(Canvas canvas, Paint paint, int x, int y, int width) {
60 |             int halfWidth = width / 2;
61 | 
62 |             path.moveTo(x, y - halfWidth); // Top
63 |             path.lineTo(x - halfWidth, y + halfWidth); // Bottom left
64 |             path.lineTo(x + halfWidth, y + halfWidth); // Bottom right
65 |             path.lineTo(x, y - halfWidth); // Back to Top
66 |             path.close();
67 | 
68 |             canvas.drawPath(path, paint);
69 |         }
70 |     }
71 | }


--------------------------------------------------------------------------------
/Multithreading/MainActivity.java:
--------------------------------------------------------------------------------
 1 | package com.example.multithreading;
 2 | 
 3 | import android.app.Activity;
 4 | import android.os.Bundle;
 5 | import android.os.Handler;
 6 | import android.view.View;
 7 | import android.widget.TextView;
 8 | public class MainActivity extends Activity {
 9 |     private TextView tvOutput;
10 |     private static final int t1 = 1;
11 |     private static final int t2 = 2;
12 |     private static final int t3 = 3;
13 |     @Override
14 |     public void onCreate(Bundle savedInstanceState) {
15 |         super.onCreate(savedInstanceState);
16 |         setContentView(R.layout.activity_main);
17 |         tvOutput = (TextView) findViewById(R.id.textView1);
18 |     }
19 |     public void fetchData(View v) {
20 |         tvOutput.setText("Main thread");
21 |         thread1.start();
22 |         thread2.start();
23 |         thread3.start();
24 |     }
25 |     Thread thread1 = new Thread(new Runnable() {
26 |         @Override
27 |         public void run() {
28 |             for (int i = 0; i < 5; i++) {
29 |                 try {
30 |                     Thread.sleep(1000);
31 |                 } catch (InterruptedException e) {
32 |                     e.printStackTrace();
33 |                 }
34 |                 handler.sendEmptyMessage(t1);
35 |             }
36 |         }
37 |     });
38 |     Thread thread2 = new Thread(new Runnable() {
39 |         @Override
40 |         public void run() {
41 |             for (int i = 0; i < 5; i++) {
42 |                 try {
43 |                     Thread.sleep(1000);
44 |                 } catch (InterruptedException e) {
45 |                     e.printStackTrace();
46 |                 }
47 |                 handler.sendEmptyMessage(t2);
48 |             }
49 |         }
50 |     });
51 |     Thread thread3 = new Thread(new Runnable() {
52 |         @Override
53 |         public void run() {
54 |             for (int i = 0; i < 5; i++) {
55 |                 try {
56 |                     Thread.sleep(1000);
57 |                 } catch (InterruptedException e) {
58 |                     e.printStackTrace();
59 |                 }
60 |                 handler.sendEmptyMessage(t3);
61 |             }
62 |         }
63 |     });
64 |     Handler handler = new Handler() {
65 |         public void handleMessage(android.os.Message msg) {
66 |             if(msg.what == t1) {
67 |                 tvOutput.append("\nIn thread 1");
68 |             }
69 |             if(msg.what == t2) {
70 |                 tvOutput.append("\nIn thread 2");
71 |             }
72 |             if(msg.what == t3) {
73 |                 tvOutput.append("\nIn thread 3");
74 |             }
75 |         }
76 |     };
77 | }
78 | 


--------------------------------------------------------------------------------
/Email/activity_main.xml:
--------------------------------------------------------------------------------
 1 | <?xml version="1.0" encoding="utf-8"?>
 2 | <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3 |     xmlns:app="http://schemas.android.com/apk/res-auto"
 4 |     xmlns:tools="http://schemas.android.com/tools"
 5 |     android:layout_width="match_parent"
 6 |     android:layout_height="match_parent"
 7 |     tools:context=".MainActivity"
 8 |     android:orientation="vertical"
 9 |     android:layout_margin="10sp">
10 | 
11 |     <TextView
12 |         android:layout_width="match_parent"
13 |         android:layout_height="wrap_content"
14 |         android:text="From: Dhanavidhya"
15 |         android:textSize="30sp"
16 |         android:layout_margin="10sp"
17 |         />
18 |     <TextView
19 |         android:layout_width="match_parent"
20 |         android:layout_height="wrap_content"
21 |         android:text="To"
22 |         android:textSize="30sp"
23 |         android:layout_margin="10sp"
24 |         />
25 |     <EditText
26 |         android:layout_width="match_parent"
27 |         android:layout_height="wrap_content"
28 |         android:id="@+id/tofield"
29 |         android:textSize="20sp"
30 |         android:layout_margin="10sp"
31 |         />
32 |     <TextView
33 |         android:layout_width="match_parent"
34 |         android:layout_height="wrap_content"
35 |         android:text="Subject"
36 |         android:textSize="30sp"
37 |         android:layout_margin="10sp"
38 |         />
39 |     <EditText
40 |         android:layout_width="match_parent"
41 |         android:layout_height="wrap_content"
42 |         android:id="@+id/subfield"
43 |         android:textSize="20sp"
44 |         android:layout_margin="10sp"
45 |         />
46 |     <TextView
47 |         android:layout_width="match_parent"
48 |         android:layout_height="wrap_content"
49 |         android:text="Message"
50 |         android:textSize="30sp"
51 |         android:layout_margin="10sp"
52 |         />
53 | 
54 |     <com.google.android.material.textfield.TextInputLayout
55 |         style="@style/Widget.MaterialComponents.TextInputLayout.OutlinedBox"
56 |         android:layout_width="347dp"
57 |         android:layout_height="wrap_content"
58 |         android:layout_margin="5sp">
59 | 
60 |         <com.google.android.material.textfield.TextInputEditText
61 |             android:id="@+id/msgfield"
62 |             android:layout_width="320dp"
63 |             android:layout_height="54dp"
64 |             android:layout_margin="10sp"
65 |             android:ems="10"
66 |             android:gravity="start|top" />
67 |     </com.google.android.material.textfield.TextInputLayout>
68 |     <Button
69 |         android:layout_width="match_parent"
70 |         android:layout_height="wrap_content"
71 |         android:text="Send"
72 |         android:id="@+id/snd"
73 |         android:layout_margin="15sp"/>
74 | 
75 | </LinearLayout>


--------------------------------------------------------------------------------
/Layouts/Horizontal/activity_main.xml:
--------------------------------------------------------------------------------
 1 | <?xml version="1.0" encoding="utf-8"?>
 2 | <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent"
 3 |     android:layout_height="fill_parent">
 4 | 
 5 | 
 6 |     <LinearLayout
 7 |         android:layout_width="match_parent"
 8 |         android:layout_height="702dp"
 9 | 
10 |         >
11 | 
12 |         <HorizontalScrollView
13 |             android:id="@+id/horizontalScrollView"
14 |             android:layout_width="446dp"
15 |             android:layout_height="119dp">
16 | 
17 |             <LinearLayout
18 |                 android:layout_width="wrap_content"
19 |                 android:layout_height="wrap_content"
20 |                 android:orientation="horizontal">
21 | 
22 |                 <Button
23 |                     android:id="@+id/button1"
24 |                     android:layout_width="wrap_content"
25 |                     android:layout_height="match_parent"
26 |                     android:text="JAVA" />
27 | 
28 |                 <Button
29 |                     android:id="@+id/button2"
30 |                     android:layout_width="wrap_content"
31 |                     android:layout_height="wrap_content"
32 |                     android:text="C" />
33 | 
34 |                 <Button
35 |                     android:id="@+id/button3"
36 |                     android:layout_width="wrap_content"
37 |                     android:layout_height="wrap_content"
38 |                     android:text="PYTHON" />
39 | 
40 |                 <Button
41 |                     android:id="@+id/button4"
42 |                     android:layout_width="wrap_content"
43 |                     android:layout_height="wrap_content"
44 |                     android:text="KOTLIN" />
45 | 
46 |                 <Button
47 |                     android:id="@+id/button5"
48 |                     android:layout_width="wrap_content"
49 |                     android:layout_height="wrap_content"
50 |                     android:text="C++" />
51 | 
52 |                 <Button
53 |                     android:id="@+id/button6"
54 |                     android:layout_width="wrap_content"
55 |                     android:layout_height="wrap_content"
56 |                     android:text="FLUTTER" />
57 | 
58 |                 <Button
59 |                     android:id="@+id/button7"
60 |                     android:layout_width="wrap_content"
61 |                     android:layout_height="wrap_content"
62 |                     android:text="C#" />
63 | 
64 |                 <Button
65 |                     android:id="@+id/button8"
66 | 
67 |                     android:layout_width="wrap_content"
68 |                     android:layout_height="wrap_content"
69 |                     android:text="R" />
70 |             </LinearLayout>
71 | 
72 | 
73 |         </HorizontalScrollView>
74 |     </LinearLayout>
75 | </RelativeLayout>
76 | 


--------------------------------------------------------------------------------
/ArithmeticCalculator/activty_main.xml:
--------------------------------------------------------------------------------
 1 | <?xml version="1.0" encoding="utf-8"?>
 2 | <LinearLayout
 3 |     xmlns:android="http://schemas.android.com/apk/res/android"
 4 |     android:orientation="vertical"
 5 |     android:layout_width="match_parent"
 6 |     android:layout_height="match_parent"
 7 |     android:layout_margin="20dp">
 8 | 
 9 |     <LinearLayout
10 |         android:id="@+id/linearLayout1"
11 |         android:layout_width="match_parent"
12 |         android:layout_height="wrap_content"
13 |         android:layout_margin="20dp">
14 | 
15 |         <EditText
16 |             android:id="@+id/editText1"
17 |             android:layout_width="match_parent"
18 |             android:layout_height="wrap_content"
19 |             android:layout_weight="1"
20 |             android:inputType="numberDecimal"
21 |             android:textSize="20sp" />
22 | 
23 |         <EditText
24 |             android:id="@+id/editText2"
25 |             android:layout_width="match_parent"
26 |             android:layout_height="wrap_content"
27 |             android:layout_weight="1"
28 |             android:inputType="numberDecimal"
29 |             android:textSize="20sp" />
30 | 
31 |     </LinearLayout>
32 | 
33 |     <LinearLayout
34 |         android:id="@+id/linearLayout2"
35 |         android:layout_width="match_parent"
36 |         android:layout_height="wrap_content"
37 |         android:layout_margin="20dp">
38 | 
39 |         <Button
40 |             android:id="@+id/Add"
41 |             android:layout_width="match_parent"
42 |             android:layout_height="wrap_content"
43 |             android:layout_weight="1"
44 |             android:text="+"
45 |             android:textSize="30sp"/>
46 | 
47 |         <Button
48 |             android:id="@+id/Sub"
49 |             android:layout_width="match_parent"
50 |             android:layout_height="wrap_content"
51 |             android:layout_weight="1"
52 |             android:text="-"
53 |             android:textSize="30sp"/>
54 | 
55 |         <Button
56 |             android:id="@+id/Mul"
57 |             android:layout_width="match_parent"
58 |             android:layout_height="wrap_content"
59 |             android:layout_weight="1"
60 |             android:text="*"
61 |             android:textSize="30sp"/>
62 | 
63 |         <Button
64 |             android:id="@+id/Div"
65 |             android:layout_width="match_parent"
66 |             android:layout_height="wrap_content"
67 |             android:layout_weight="1"
68 |             android:text="/"
69 |             android:textSize="30sp"/>
70 | 
71 |     </LinearLayout>
72 | 
73 |     <TextView
74 |         android:id="@+id/textView"
75 |         android:layout_width="match_parent"
76 |         android:layout_height="wrap_content"
77 |         android:layout_marginTop="50dp"
78 |         android:text="Answer is"
79 |         android:textSize="30sp"
80 |         android:gravity="center"/>
81 | 
82 | </LinearLayout>
83 | 


--------------------------------------------------------------------------------
/Layouts/Vertical/activity_main.xml:
--------------------------------------------------------------------------------
 1 | <?xml version="1.0" encoding="utf-8"?>
 2 | <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3 |     xmlns:app="http://schemas.android.com/apk/res-auto"
 4 |     xmlns:tools="http://schemas.android.com/tools"
 5 |     android:layout_width="match_parent"
 6 |     android:layout_height="match_parent"
 7 |     tools:context=".MainActivity">
 8 | 
 9 |     <ScrollView
10 |         android:layout_width="218dp"
11 |         android:layout_height="512dp"
12 |         android:layout_alignParentTop="true"
13 |         android:layout_alignParentEnd="true"
14 |         android:layout_centerVertical="true"
15 |         android:layout_marginTop="100dp"
16 |         android:layout_marginEnd="85dp">
17 | 
18 | 
19 |         <LinearLayout
20 |             android:layout_width="wrap_content"
21 |             android:layout_height="wrap_content"
22 |             android:orientation="vertical">
23 | 
24 |             <Button
25 |                 android:layout_width="169dp"
26 |                 android:layout_height="100dp"
27 |                 android:text="Java"
28 |                 app:backgroundTint="#651FFF">
29 | 
30 |             </Button>
31 | 
32 |             <Button
33 |                 android:layout_width="match_parent"
34 |                 android:layout_height="100dp"
35 |                 android:text="C"></Button>
36 | 
37 |             <Button
38 |                 android:layout_width="match_parent"
39 |                 android:layout_height="100dp"
40 |                 android:text="Python">
41 | 
42 |             </Button>
43 | 
44 |             <Button
45 |                 android:layout_width="match_parent"
46 |                 android:layout_height="100dp"
47 |                 android:text="Kotlin"></Button>
48 | 
49 |             <Button
50 |                 android:layout_width="match_parent"
51 |                 android:layout_height="100dp"
52 |                 android:text="C++">
53 | 
54 | 
55 |             </Button>
56 | 
57 |             <Button
58 |                 android:layout_width="match_parent"
59 |                 android:layout_height="100dp"
60 |                 android:text="Flutter"></Button>
61 | 
62 |             <Button
63 |                 android:layout_width="match_parent"
64 |                 android:layout_height="100dp"
65 |                 android:text="C#"></Button>
66 |         </LinearLayout>
67 | 
68 |     </ScrollView>
69 | 
70 |     <TextView
71 |         android:id="@+id/textView6"
72 |         android:layout_width="wrap_content"
73 |         android:layout_height="wrap_content"
74 |         android:layout_alignParentTop="true"
75 |         android:layout_alignParentEnd="true"
76 |         android:layout_centerHorizontal="true"
77 |         android:layout_marginTop="45dp"
78 |         android:layout_marginEnd="50dp"
79 |         android:text="Programming Languages"
80 |         android:textAppearance="@style/TextAppearance.AppCompat.Large"
81 |         app:textAllCaps="true" />
82 | </RelativeLayout>
83 | 


--------------------------------------------------------------------------------
/ArithmeticCalculator/MainActivity.java:
--------------------------------------------------------------------------------
 1 | package com.example.arithmeticcalculator;
 2 | 
 3 | import android.os.Bundle;
 4 | import androidx.appcompat.app.AppCompatActivity;
 5 | import android.text.TextUtils;
 6 | import android.view.View;
 7 | import android.view.View.OnClickListener;
 8 | import android.widget.Button;
 9 | import android.widget.EditText;
10 | import android.widget.TextView;
11 | 
12 | public class MainActivity extends AppCompatActivity implements OnClickListener
13 | {
14 |     //Defining the Views
15 |     EditText Num1;
16 |     EditText Num2;
17 |     Button Add;
18 |     Button Sub;
19 |     Button Mul;
20 |     Button Div;
21 |     TextView Result;
22 | 
23 |     @Override
24 |     public void onCreate(Bundle savedInstanceState)
25 |     {
26 |         super.onCreate(savedInstanceState);
27 |         setContentView(R.layout.activity_main);
28 | 
29 |         //Referring the Views
30 |         Num1 = (EditText) findViewById(R.id.editText1);
31 |         Num2 = (EditText) findViewById(R.id.editText2);
32 |         Add = (Button) findViewById(R.id.Add);
33 |         Sub = (Button) findViewById(R.id.Sub);
34 |         Mul = (Button) findViewById(R.id.Mul);
35 |         Div = (Button) findViewById(R.id.Div);
36 |         Result = (TextView) findViewById(R.id.textView);
37 | 
38 |         // set a listener
39 |         Add.setOnClickListener(this);
40 |         Sub.setOnClickListener(this);
41 |         Mul.setOnClickListener(this);
42 |         Div.setOnClickListener(this);
43 |     }
44 | 
45 |     @Override
46 |     public void onClick (View v)
47 |     {
48 | 
49 |         float num1 = 0;
50 |         float num2 = 0;
51 |         float result = 0;
52 |         String oper = "";
53 | 
54 |         // check if the fields are empty
55 |         if (TextUtils.isEmpty(Num1.getText().toString()) || TextUtils.isEmpty(Num2.getText().toString()))
56 |             return;
57 | 
58 |         // read EditText and fill variables with numbers
59 |         num1 = Float.parseFloat(Num1.getText().toString());
60 |         num2 = Float.parseFloat(Num2.getText().toString());
61 | 
62 |         // defines the button that has been clicked and performs the corresponding operation
63 |         // write operation into oper, we will use it later for output
64 |         switch (v.getId())
65 |         {
66 |             case R.id.Add:
67 |                 oper = "+";
68 |                 result = num1 + num2;
69 |                 break;
70 |             case R.id.Sub:
71 |                 oper = "-";
72 |                 result = num1 - num2;
73 |                 break;
74 |             case R.id.Mul:
75 |                 oper = "*";
76 |                 result = num1 * num2;
77 |                 break;
78 |             case R.id.Div:
79 |                 oper = "/";
80 |                 result = num1 / num2;
81 |                 break;
82 |             default:
83 |                 break;
84 |         }
85 |         // form the output line
86 |         Result.setText(num1 + " " + oper + " " + num2 + " = " + result);
87 |     }
88 | }
89 | 
90 | 


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/Database Connectivity/activity_main.xml:
--------------------------------------------------------------------------------
  1 | <?xml version="1.0" encoding="utf-8"?>
  2 | <AbsoluteLayout xmlns:android="http://schemas.android.com/apk/res/android"
  3 |     android:layout_width="match_parent"
  4 |     android:layout_height="match_parent">
  5 | 
  6 |     <TextView
  7 |         android:layout_width="wrap_content"
  8 |         android:layout_height="wrap_content"
  9 |         android:layout_x="149dp"
 10 |         android:layout_y="26dp"
 11 |         android:text="VCET"
 12 |         android:textSize="30sp" />
 13 | 
 14 |     <TextView
 15 |         android:layout_width="wrap_content"
 16 |         android:layout_height="wrap_content"
 17 |         android:layout_x="90dp"
 18 |         android:layout_y="73dp"
 19 |         android:text="Student Detials"
 20 |         android:textSize="30sp" />
 21 |     <TextView
 22 |         android:layout_width="wrap_content"
 23 |         android:layout_height="wrap_content"
 24 |         android:layout_x="18dp"
 25 |         android:layout_y="153dp"
 26 |         android:text="Enter Rollno:"
 27 |         android:textSize="20sp" />
 28 |     <EditText
 29 |         android:id="@+id/Rollno"
 30 |         android:layout_width="150dp"
 31 |         android:layout_height="wrap_content"
 32 |         android:layout_x="167dp"
 33 |         android:layout_y="133dp"
 34 |         android:inputType="number"
 35 |         android:textSize="20sp" />
 36 |     <TextView
 37 |         android:layout_width="wrap_content"
 38 |         android:layout_height="wrap_content"
 39 |         android:layout_x="28dp"
 40 |         android:layout_y="217dp"
 41 |         android:text="Enter Name:"
 42 |         android:textSize="20sp" />
 43 |     <EditText
 44 |         android:id="@+id/Name"
 45 |         android:layout_width="150dp"
 46 |         android:layout_height="wrap_content"
 47 |         android:layout_x="171dp"
 48 |         android:layout_y="198dp"
 49 |         android:inputType="text"
 50 |         android:textSize="20sp" />
 51 |     <TextView
 52 |         android:layout_width="wrap_content"
 53 |         android:layout_height="wrap_content"
 54 |         android:layout_x="27dp"
 55 |         android:layout_y="280dp"
 56 |         android:text="Enter Marks:"
 57 |         android:textSize="20sp" />
 58 |     <EditText
 59 |         android:id="@+id/Marks"
 60 |         android:layout_width="150dp"
 61 |         android:layout_height="wrap_content"
 62 |         android:layout_x="175dp"
 63 |         android:layout_y="266dp"
 64 |         android:inputType="number"
 65 |         android:textSize="20sp" />
 66 |     <Button
 67 |         android:id="@+id/Insert"
 68 |         android:layout_width="150dp"
 69 |         android:layout_height="wrap_content"
 70 |         android:layout_x="22dp"
 71 |         android:layout_y="381dp"
 72 |         android:text="Insert"
 73 |         android:textSize="30dp" />
 74 |     <Button
 75 |         android:id="@+id/Delete"
 76 |         android:layout_width="190dp"
 77 |         android:layout_height="wrap_content"
 78 |         android:layout_x="205dp"
 79 |         android:layout_y="383dp"
 80 |         android:text="Delete"
 81 |         android:textSize="30dp" />
 82 |     <Button
 83 |         android:id="@+id/Update"
 84 |         android:layout_width="174dp"
 85 |         android:layout_height="wrap_content"
 86 |         android:layout_x="16dp"
 87 |         android:layout_y="496dp"
 88 |         android:text="Update"
 89 |         android:textSize="30dp" />
 90 |     <Button
 91 |         android:id="@+id/View"
 92 |         android:layout_width="150dp"
 93 |         android:layout_height="wrap_content"
 94 |         android:layout_x="213dp"
 95 |         android:layout_y="493dp"
 96 |         android:text="View"
 97 |         android:textSize="30dp" />
 98 |     <Button
 99 |         android:id="@+id/ViewAll"
100 |         android:layout_width="200dp"
101 |         android:layout_height="wrap_content"
102 |         android:layout_x="99dp"
103 |         android:layout_y="616dp"
104 |         android:text="View All"
105 |         android:textSize="30dp" />
106 | </AbsoluteLayout>


--------------------------------------------------------------------------------
/Billing/activity_main.xml:
--------------------------------------------------------------------------------
  1 | <androidx.constraintlayout.widget.ConstraintLayout
  2 |     xmlns:android="http://schemas.android.com/apk/res/android"
  3 |     xmlns:app="http://schemas.android.com/apk/res-auto"
  4 |     xmlns:tools="http://schemas.android.com/tools"
  5 |     android:layout_width="match_parent"
  6 |     android:layout_height="match_parent"
  7 |     tools:context=".MainActivity">
  8 |     <CheckBox
  9 |         android:id="@+id/chips"
 10 |         android:layout_width="wrap_content"
 11 |         android:layout_height="wrap_content"
 12 |         android:layout_marginStart="19dp"
 13 |         android:layout_marginBottom="11dp"
 14 |         android:text="Chips"
 15 |         app:layout_constraintBottom_toTopOf="@+id/cakes"
 16 |         app:layout_constraintStart_toStartOf="parent"/>
 17 |     <CheckBox
 18 |         android:id="@+id/cakes"
 19 |         android:layout_width="wrap_content"
 20 |         android:layout_height="wrap_content"
 21 |         android:layout_marginStart="2dp"
 22 |         android:text="Cakes"
 23 |         app:layout_constraintBaseline_toBaselineOf="@+id/numCakes"
 24 |         app:layout_constraintStart_toStartOf="@+id/chips"/>
 25 |     <CheckBox
 26 |         android:id="@+id/candy"
 27 |         android:layout_width="wrap_content"
 28 |         android:layout_height="wrap_content"
 29 |         android:layout_marginStart="19dp"
 30 |         android:layout_marginTop="210dp"
 31 |         android:text="Candies"
 32 |         app:layout_constraintStart_toStartOf="parent"
 33 |         app:layout_constraintTop_toTopOf="parent"/>
 34 |     <CheckBox
 35 |         android:id="@+id/cookie"
 36 |         android:layout_width="wrap_content"
 37 |         android:layout_height="wrap_content"
 38 |         android:layout_marginEnd="8dp"
 39 |         android:text="Cookies"
 40 |         app:layout_constraintBaseline_toBaselineOf="@+id/numCookies"
 41 |         app:layout_constraintEnd_toStartOf="@+id/numCookies"/>
 42 |     <EditText
 43 |         android:id="@+id/numChips"
 44 |         android:layout_width="wrap_content"
 45 |         android:layout_height="wrap_content"
 46 |         android:layout_marginStart="24dp"
 47 |         android:ems="10"
 48 |         android:inputType="textPersonName"
 49 |         app:layout_constraintBaseline_toBaselineOf="@+id/chips"
 50 |         app:layout_constraintStart_toEndOf="@+id/chips"/>
 51 |     <EditText
 52 |         android:id="@+id/numCakes"
 53 |         android:layout_width="wrap_content"
 54 |         android:layout_height="wrap_content"
 55 |         android:layout_marginStart="8dp"
 56 |         android:layout_marginBottom="8dp"
 57 |         android:ems="10"
 58 |         android:inputType="textPersonName"
 59 |         app:layout_constraintBottom_toTopOf="@+id/candy"
 60 |         app:layout_constraintStart_toEndOf="@+id/candy"/>
 61 |     <EditText
 62 |         android:id="@+id/numCandies"
 63 |         android:layout_width="wrap_content"
 64 |         android:layout_height="wrap_content"
 65 |         android:layout_marginStart="8dp"
 66 |         android:layout_marginTop="6dp"
 67 |         android:ems="10"
 68 |         android:inputType="textPersonName"
 69 |         app:layout_constraintStart_toEndOf="@+id/candy"
 70 |         app:layout_constraintTop_toTopOf="@+id/candy"/>
 71 |     <EditText
 72 |         android:id="@+id/numCookies"
 73 |         android:layout_width="wrap_content"
 74 |         android:layout_height="wrap_content"
 75 |         android:layout_marginStart="2dp"
 76 |         android:layout_marginTop="8dp"
 77 |         android:ems="10"
 78 |         android:inputType="textPersonName"
 79 |         app:layout_constraintStart_toStartOf="@+id/numCandies"
 80 |         app:layout_constraintTop_toBottomOf="@+id/numCandies"/>
 81 |     <Button
 82 |         android:id="@+id/submit"
 83 |         android:layout_width="wrap_content"
 84 |         android:layout_height="wrap_content"
 85 |         android:layout_marginTop="70dp"
 86 |         android:text="Submit"
 87 |         app:layout_constraintEnd_toEndOf="parent"
 88 |         app:layout_constraintStart_toStartOf="parent"
 89 |         app:layout_constraintTop_toBottomOf="@+id/numCookies"/>
 90 |     <TextView
 91 |         android:id="@+id/result"
 92 |         android:layout_width="wrap_content"
 93 |         android:layout_height="wrap_content"
 94 |         android:layout_marginTop="83dp"
 95 |         android:layout_marginEnd="109dp"
 96 |         android:text="Total: 0 Rs."
 97 |         android:textAppearance="@style/TextAppearance.AppCompat.Display1"
 98 |         app:layout_constraintEnd_toEndOf="parent"
 99 |         app:layout_constraintTop_toBottomOf="@+id/submit"/>
100 | </androidx.constraintlayout.widget.ConstraintLayout>


--------------------------------------------------------------------------------
/Location Based Services/GPStrace.java:
--------------------------------------------------------------------------------
  1 | package com.example.location1;
  2 | import android.annotation.SuppressLint;
  3 | import android.app.AlertDialog;
  4 | import android.app.Service;
  5 | import android.content.Context;
  6 | import android.content.DialogInterface;
  7 | import android.content.Intent;
  8 | import android.location.Location;
  9 | import android.location.LocationListener;
 10 | import android.location.LocationManager;
 11 | import android.os.Bundle;
 12 | import android.os.IBinder;
 13 | import android.provider.Settings;
 14 | public class GPStrace extends Service implements LocationListener{
 15 |     private final Context context;
 16 |     boolean isGPSEnabled=false;
 17 |     boolean canGetLocation=false;
 18 |     boolean isNetworkEnabled=false;
 19 |     Location location;
 20 |     double latitude;
 21 |     double longtitude;
 22 |     private static final long MIN_DISTANCE_CHANGE_FOR_UPDATES=10;
 23 |     private static final long MIN_TIME_BW_UPDATES=1000*60*1;
 24 |     protected LocationManager locationManager;
 25 |     public GPStrace(Context context)
 26 |     {
 27 |         this.context=context;
 28 |         getLocation();
 29 |     }
 30 |     @SuppressLint("MissingPermission")
 31 |     public Location getLocation()
 32 |     {
 33 |         try{
 34 |             locationManager=(LocationManager) context.getSystemService(LOCATION_SERVICE);
 35 |             isGPSEnabled=locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER);
 36 |             isNetworkEnabled=locationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER);
 37 |             if(!isGPSEnabled && !isNetworkEnabled){
 38 |             }else{
 39 |                 this.canGetLocation=true;
 40 |                 if(isNetworkEnabled){
 41 |                     locationManager.requestLocationUpdates(LocationManager.NETWORK_PROVIDER, MIN_TIME_BW_UPDATES,MIN_DISTANCE_CHANGE_FOR_UPDATES,this);
 42 |                 }
 43 |                 if(locationManager!=null){
 44 |                     location=locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
 45 |                     if(location !=null){
 46 |                         latitude=location.getLatitude();
 47 |                         longtitude=location.getLongitude();
 48 |                     }
 49 |                 }
 50 |             }
 51 |             if(isGPSEnabled){
 52 |                 if(location==null){
 53 |                     locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER,MIN_TIME_BW_UPDATES, MIN_DISTANCE_CHANGE_FOR_UPDATES, this);
 54 |                     if(locationManager!=null){
 55 |                         location=locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
 56 |                         if(location!=null){
 57 |                             latitude=location.getLatitude();
 58 |                             longtitude=location.getLongitude();
 59 |                         }
 60 |                     }
 61 |                 }
 62 |             }
 63 |         }
 64 |         catch(Exception e)
 65 |         {
 66 |             e.printStackTrace();
 67 |         }
 68 |         return location;
 69 |     }
 70 |     public void stopUsingGPS(){
 71 |         if(locationManager!=null){
 72 |             locationManager.removeUpdates(GPStrace.this);
 73 |         }
 74 |     }
 75 |     public double getLatitude(){
 76 |         if(location!=null){
 77 |             latitude=location.getLatitude();
 78 |         }
 79 |         return latitude;
 80 |     }
 81 |     public double getLongtiude(){
 82 |         if(location!=null){
 83 |             longtitude=location.getLatitude();
 84 |         }
 85 |         return longtitude;
 86 |     }
 87 |     public boolean canGetLocation(){
 88 |         return this.canGetLocation;
 89 |     }
 90 |     public void showSettingAlert(){
 91 |         AlertDialog.Builder alertDialog=new AlertDialog.Builder(context);
 92 |         alertDialog.setTitle("GPS is settings");
 93 |         alertDialog.setMessage("GPS is not enabled.Do you want to go to setting menu?");
 94 |         alertDialog.setPositiveButton("settings", new DialogInterface.OnClickListener() {
 95 |             @Override
 96 |             public void onClick(DialogInterface dialog,int which){
 97 |                 Intent intent=new Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS);
 98 |                 context.startActivity(intent);
 99 |             }
100 |         });
101 |         alertDialog.setNegativeButton("cancel", new DialogInterface.OnClickListener() {
102 |             @Override
103 |             public void onClick(DialogInterface dialog, int which) {
104 |                 dialog.cancel();
105 |             }
106 |         });
107 |         alertDialog.show();
108 |     }
109 |     @Override
110 |     public void onLocationChanged(Location location) {
111 |     }
112 |     @Override
113 |     public void onProviderDisabled(String provider) {
114 |     }
115 |     @Override
116 |     public void onProviderEnabled(String provider) {
117 |     }
118 |     @Override
119 |     public void onStatusChanged(String provider, int status, Bundle extras) {
120 |     }
121 |     @Override
122 |     public IBinder onBind(Intent intent) {
123 |         return null;
124 |     }
125 | }


--------------------------------------------------------------------------------
/Database Connectivity/MainActivity.java:
--------------------------------------------------------------------------------
  1 | package com.example.databaseconnectivity;
  2 | 
  3 | 
  4 | import android.app.Activity;
  5 | import android.app.AlertDialog.Builder;
  6 | import android.content.Context;
  7 | import android.database.Cursor;
  8 | import android.database.sqlite.SQLiteDatabase;
  9 | import android.os.Bundle;
 10 | import android.view.View;
 11 | import android.view.View.OnClickListener;
 12 | import android.widget.Button;
 13 | import android.widget.EditText;
 14 | 
 15 | public class MainActivity extends Activity implements OnClickListener
 16 | {
 17 |     EditText Rollno,Name,Marks;
 18 |     Button Insert,Delete,Update,View,ViewAll;
 19 |     SQLiteDatabase db;
 20 |     /** Called when the activity is first created. */
 21 |     @Override
 22 |     public void onCreate(Bundle savedInstanceState)
 23 |     {
 24 |         super.onCreate(savedInstanceState);
 25 |         setContentView(R.layout.activity_main);
 26 | 
 27 |         Rollno=(EditText)findViewById(R.id.Rollno);
 28 |         Name=(EditText)findViewById(R.id.Name);
 29 |         Marks=(EditText)findViewById(R.id.Marks);
 30 |         Insert=(Button)findViewById(R.id.Insert);
 31 |         Delete=(Button)findViewById(R.id.Delete);
 32 |         Update=(Button)findViewById(R.id.Update);
 33 |         View=(Button)findViewById(R.id.View);
 34 |         ViewAll=(Button)findViewById(R.id.ViewAll);
 35 | 
 36 |         Insert.setOnClickListener(this);
 37 |         Delete.setOnClickListener(this);
 38 |         Update.setOnClickListener(this);
 39 |         View.setOnClickListener(this);
 40 |         ViewAll.setOnClickListener(this);
 41 | 
 42 |         // Creating database and table
 43 |         db=openOrCreateDatabase("StudentDB", Context.MODE_PRIVATE, null);
 44 |         db.execSQL("CREATE TABLE IF NOT EXISTS student(rollno VARCHAR,name VARCHAR,marks VARCHAR);");
 45 |     }
 46 |     public void onClick(View view)
 47 |     {
 48 |         // Inserting a record to the Student table
 49 |         if(view==Insert)
 50 |         {
 51 |             // Checking for empty fields
 52 |             if(Rollno.getText().toString().trim().length()==0||
 53 |                     Name.getText().toString().trim().length()==0||
 54 |                     Marks.getText().toString().trim().length()==0)
 55 |             {
 56 |                 showMessage("Error", "Please enter all values");
 57 |                 return;
 58 |             }
 59 |             db.execSQL("INSERT INTO student VALUES('"+Rollno.getText()+"','"+Name.getText()+
 60 |                     "','"+Marks.getText()+"');");
 61 |             showMessage("Success", "Record added");
 62 |             clearText();
 63 |         }
 64 |         // Deleting a record from the Student table
 65 |         if(view==Delete)
 66 |         {
 67 |             // Checking for empty roll number
 68 |             if(Rollno.getText().toString().trim().length()==0)
 69 |             {
 70 |                 showMessage("Error", "Please enter Rollno");
 71 |                 return;
 72 |             }
 73 |             Cursor c=db.rawQuery("SELECT * FROM student WHERE rollno='"+Rollno.getText()+"'", null);
 74 |             if(c.moveToFirst())
 75 |             {
 76 |                 db.execSQL("DELETE FROM student WHERE rollno='"+Rollno.getText()+"'");
 77 |                 showMessage("Success", "Record Deleted");
 78 |             }
 79 |             else
 80 |             {
 81 |                 showMessage("Error", "Invalid Rollno");
 82 |             }
 83 |             clearText();
 84 |         }
 85 |         // Updating a record in the Student table
 86 |         if(view==Update)
 87 |         {
 88 |             // Checking for empty roll number
 89 |             if(Rollno.getText().toString().trim().length()==0)
 90 |             {
 91 |                 showMessage("Error", "Please enter Rollno");
 92 |                 return;
 93 |             }
 94 |             Cursor c=db.rawQuery("SELECT * FROM student WHERE rollno='"+Rollno.getText()+"'", null);
 95 |             if(c.moveToFirst()) {
 96 |                 db.execSQL("UPDATE student SET name='" + Name.getText() + "',marks='" + Marks.getText() +
 97 |                         "' WHERE rollno='"+Rollno.getText()+"'");
 98 |                 showMessage("Success", "Record Modified");
 99 |             }
100 |             else {
101 |                 showMessage("Error", "Invalid Rollno");
102 |             }
103 |             clearText();
104 |         }
105 |         // Display a record from the Student table
106 |         if(view==View)
107 |         {
108 |             // Checking for empty roll number
109 |             if(Rollno.getText().toString().trim().length()==0)
110 |             {
111 |                 showMessage("Error", "Please enter Rollno");
112 |                 return;
113 |             }
114 |             Cursor c=db.rawQuery("SELECT * FROM student WHERE rollno='"+Rollno.getText()+"'", null);
115 |             if(c.moveToFirst())
116 |             {
117 |                 Name.setText(c.getString(1));
118 |                 Marks.setText(c.getString(2));
119 |             }
120 |             else
121 |             {
122 |                 showMessage("Error", "Invalid Rollno");
123 |                 clearText();
124 |             }
125 |         }
126 |         // Displaying all the records
127 |         if(view==ViewAll)
128 |         {
129 |             Cursor c=db.rawQuery("SELECT * FROM student", null);
130 |             if(c.getCount()==0)
131 |             {
132 |                 showMessage("Error", "No records found");
133 |                 return;
134 |             }
135 |             StringBuffer buffer=new StringBuffer();
136 |             while(c.moveToNext())
137 |             {
138 |                 buffer.append("Rollno: "+c.getString(0)+"\n");
139 |                 buffer.append("Name: "+c.getString(1)+"\n");
140 |                 buffer.append("Marks: "+c.getString(2)+"\n\n");
141 |             }
142 |             showMessage("Student Details", buffer.toString());
143 |         }
144 |     }
145 |     public void showMessage(String title,String message)
146 |     {
147 |         Builder builder=new Builder(this);
148 |         builder.setCancelable(true);
149 |         builder.setTitle(title);
150 |         builder.setMessage(message);
151 |         builder.show();
152 |     }
153 |     public void clearText()
154 |     {
155 |         Rollno.setText("");
156 |         Name.setText("");
157 |         Marks.setText("");
158 |         Rollno.requestFocus();
159 |     }
160 | }
161 | 


--------------------------------------------------------------------------------