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└── README.md


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--------------------------------------------------------------------------------
/LICENSE:
--------------------------------------------------------------------------------
 1 | MIT License
 2 | 
 3 | Copyright (c) 2020 james.lee
 4 | 
 5 | Permission is hereby granted, free of charge, to any person obtaining a copy
 6 | of this software and associated documentation files (the "Software"), to deal
 7 | in the Software without restriction, including without limitation the rights
 8 | to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 9 | copies of the Software, and to permit persons to whom the Software is
10 | furnished to do so, subject to the following conditions:
11 | 
12 | The above copyright notice and this permission notice shall be included in all
13 | copies or substantial portions of the Software.
14 | 
15 | THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 | IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 | FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 | AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 | LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 | OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21 | SOFTWARE.
22 | 


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
  1 | ## Xaml Binding
  2 |   
  3 | 이 리포지토리는 WPF Xaml Binding 개념과 기술을 활용하는데 필요한 설명을 다루는 Article입니다.
  4 | 
  5 | <a href="https://github.com/devncore/devncore"><strong>더 알아보기 »</strong></a>
  6 |   
  7 | | Star | License | Activity |
  8 | |:----:|:-------:|:--------:|
  9 | | <a href="https://github.com/devncore/wpf-xaml-binding/stargazers"><img src="https://img.shields.io/github/stars/devncore/wpf-xaml-binding" alt="Github Stars"></a> | <img src="https://img.shields.io/github/license/devncore/wpf-xaml-binding" alt="License"> | <a href="https://github.com/devncore/wpf-xaml-binding/pulse"><img src="https://img.shields.io/github/commit-activity/m/devncore/wpf-xaml-binding" alt="Commits-per-month"></a> |
 10 | 
 11 | <br />
 12 | 
 13 | ## DataContext
 14 | 
 15 | __DataContext는 FrameworkElement에 포함된 속성입니다.__  
 16 | `PresentationFramework.dll`
 17 | 
 18 | ```csharp
 19 | namespace System.Windows
 20 | {
 21 |     public class FrameworkElement : UIElement
 22 |     {
 23 |         public static readonly DependencyProperty DataContextProperty;
 24 |         public object DataContext { get; set; }
 25 |     }
 26 | }
 27 | ```
 28 | 
 29 | 그리고 WPF의 모든 UI 컨트롤은 `FrameworkElement` 클래스를 상속합니다. 
 30 | > 바인딩 또는 데이터 컨텍스트를 배워가는 시점에서 FrameworkElement를 더 깊이 연구할 필요가 없습니다.
 31 | > 하지만 모든 UI 컨트롤을 포함할 수 있는 가장 가까운 개체가 FrameworkElement라는 사실을 간단히 언급하기 위함입니다.
 32 | <br />
 33 | 
 34 | ### _DataContext is always the reference point for Binding._ 
 35 | Binding can directly recall values for the DataContext type format starting with the nearest DataContext.
 36 | ```xaml
 37 | <TextBlock Text="{Binding}" DataContext="James"/>
 38 | ```
 39 | `Text="{Binding}`에 바인딩된 값은 가장 가까운 데이터 컨텍스트인 `TextBlock`에서 직접 전달됩니다.    
 40 | 따라서 `Text`의 바인딩 결과 값은 'James'입니다.
 41 | <br />
 42 | 
 43 | - __Type integer__  
 44 | Xaml에서 DataContext에 직접 값을 할당하는 경우 정수 및 부울과 같은 값 유형에 대해 먼저 리소스 정의가 필요합니다.
 45 | 왜냐하면 모든 문자열이 문자열로 인식되기 때문입니다.
 46 | 
 47 |     #### 1. Xaml에서 System `mscrollib` 사용
 48 |     > Simple type variable type is not supported by standard.  
 49 |     > 어떤 단어로도 정의할 수 있지만 대부분 `sys` 단어를 사용합니다.
 50 |     ```xaml
 51 |     xmlns:sys="clr-namespace:System;assembly=mscorlib"
 52 |     ```
 53 | 
 54 |     #### 2. xaml에서 `YEAR` 리소스 키 생성
 55 |     > StaticResource 형식으로 생성할 유형의 값을 선언합니다.
 56 |     ```xaml
 57 |     <Window.Resources>
 58 |         <sys:Int32 x:Key="YEAR">2020</sys:Int32>
 59 |     </Window.Resources>
 60 |     ...
 61 |     <TextBlock Text="{Binding}" DataContext="{StaticResource YEAR"/>
 62 |     ```
 63 | 
 64 | - __All type of value__  
 65 | 값이 데이터 컨텍스트에 직접 바인딩되는 경우는 거의 없습니다.    
 66 | Because we're going to bind an object.
 67 |     ```xaml
 68 |     <Window.Resources>
 69 |         <sys:Boolean x:Key="IsEnabled">true</sys:Boolean>
 70 |         <sys:double x:Key="Price">7.77</sys:double>
 71 |     </Window.Resources>
 72 |     ...
 73 |     <StackPanel>
 74 |         <TextBlock Text="{Binding}" DataContext="{StaticResource IsEnabled}"/>
 75 |         <TextBlock Text="{Binding}" DataContext="{StaticResource Price}"/>
 76 |     </StackPanel>
 77 |     ```
 78 | 
 79 | - __Another type__  
 80 | 스트링뿐만 아니라 다양한 타입이 가능합니다. 데이터 컨텍스트가 객체이기 때문입니다.
 81 | <br />
 82 | 
 83 | WPF에서 바인딩을 사용할 때, 대부분의 개발자들은 DataContext의 기능 및 중요성에 대해 완전히 알지 못합니다. 특히 대규모 WPF 프로젝트를 담당하거나 참여하는 경우 애플리케이션의 DataContext 계층을 보다 명확하게 이해해야 합니다. DataContext 개념이 없으면 기능을 자유롭게 구현하는 데 한계가 있기 때문입니다.
 84 | 
 85 | <br>
 86 | 
 87 | * * *  
 88 | 
 89 | ## Binding
 90 | 
 91 | - [DataContext Binding](#datacontext-binding)
 92 | - [Element Binding](#element-binding)
 93 | - [MultiBinding](#multibinding)
 94 | - [Self Property Binding](#self-property-binding)
 95 | - [Find Ancestor Binding](#find-ancestor-binding)
 96 | - [TemplatedParent Binding](#templatedparent-binding)
 97 | - [Static Property Binding](#static-property-binding)  
 98 | <br />
 99 | 
100 | ### DataContext Binding
101 | 
102 | `string property`
103 | ```xaml
104 | <TextBox Text="{Binding Keywords}"/>
105 | ```
106 | <br />
107 | 
108 | ### Element Binding
109 | 
110 | ```xaml
111 | <CheckBox x:Name="usingEmail"/>
112 | <TextBlock Text="{Binding ElementName=usingEmail, Path=IsChecked}"/>
113 | ```
114 | <br />
115 | 
116 | ### MultiBinding
117 | 
118 | ```xaml
119 | <TextBlock Margin="5,2" Text="This disappears as the control gets focus...">
120 |   <TextBlock.Visibility>
121 |       <MultiBinding Converter="{StaticResource TextInputToVisibilityConverter}">
122 |           <Binding ElementName="txtUserEntry2" Path="Text.IsEmpty" />
123 |           <Binding ElementName="txtUserEntry2" Path="IsFocused" />
124 |       </MultiBinding>
125 |   </TextBlock.Visibility>
126 | </TextBlock>
127 | ```
128 | <br />
129 |  
130 | ### Self Property Binding
131 | 
132 | ```xaml
133 | <TextBlock x:Name="txt" Text="{Binding ElementName=txt, Path=Tag}"/>
134 | ```
135 | 자신의 속성을 바인딩해야 하는 경우 요소 바인딩 대신 `Element Binding`을 사용할 수 있습니다.    
136 | 자신의 속성을 바인딩하기 위해 `x:Name`을 선언할 필요가 없습니다.
137 | 
138 | ```xaml
139 | <TextBlock Text="{Binding RelativeSource={RelativeSource Self}, Path=Tag}"/>
140 | ```
141 | <br />
142 |  
143 | ### Find Ancestor Binding
144 | 
145 | 가장 가까운 상위 컨트롤을 기준으로 가져옵니다.
146 | 
147 | ```xaml
148 | <TextBlock Text="{Binding RelativeSource={RelativeSource AncestorType=Window}, Path=Title}"/>
149 | ```
150 | <br />
151 | 
152 | `Trigger`에서 상위 개체의 속성에 액세스할 때 유용합니다.
153 | ```xaml
154 | <DataTrigger Binding="{Binding RelativeSource={RelativeSource AncestorType=ListBoxItem}, Path=IsSelected}" Value="True">
155 |     <Setter Property="Background" Value="#DDDDDD"/>
156 | </DataTrigger>
157 | ```
158 | <br />
159 | 
160 | DataContext 객체가 있는 경우 해당 속성을 사용할 수 있습니다.    
161 | 그러나 `DataContext`(ViewModel)에 대한 접근은 가급적 피하는 것이 좋습니다.
162 | ```xaml
163 | <TextBlock Text="{Binding RelativeSource={RelativeSource AncestorType=Window}, Path=DataContext.Email}"/>
164 | ```
165 | <br />
166 | 
167 | 현재 바인딩된 `DataContext`가 아닌 다른 `DataContext`를 바인딩하려는 경우 다음 방법을 사용할 수 있습니다.
168 | ```csharp
169 | public partial class A : UserControl
170 | {
171 |     public A()
172 |     {
173 |         InitializeComponent();
174 |         DataContext = new MainViewModel();
175 |     }
176 |     
177 |     public class MainViewModel
178 |     {
179 |         public B G1VM { get; set; } = new B();
180 |         public C G2VM { get; set; } = new C();
181 |     }
182 | }
183 | ```
184 | 
185 | ```xaml
186 | <TabControl DataContext="{Binding G1VM}">
187 |   <TabItem Header="TMP">
188 |     <DataGrid ItemsSource="{Binding datagrid}" 
189 |               DataContext="{Binding RelativeSource={RelativeSource AncestorType=Window}, Path=DataContext.G1VM}"/>
190 |     <!--It can also be expressed as follows.-->
191 |     <!--<DataGrid ItemsSource="{Binding datagrid}" 
192 |                   DataContext="{Binding Parent.G2VM}"/>-->
193 |   </TabItem>
194 | </TabControl>
195 | ```
196 | <br />
197 | 
198 | ### TemplatedParent Binding
199 | 
200 | `ControlTemplate` 내에서 사용할 수 있는 메서드로 `ControlTemplate`의 자신의 속성을 가져올 수 있습니다.
201 | 
202 | ```xaml
203 | <Style TargetType="Button">
204 |   <Setter Property="Template">
205 |       <Setter.Value>
206 |           <ControlTemplate TargetType="Button">
207 |               <TextBlock Text="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Content}"/>
208 |           </ControlTemplate>
209 |       </Setter.Value>
210 |   </Setter>
211 | </Style>
212 | ```
213 | 
214 | 모든 속성 및 데이터 컨텍스트에 접근할 수 있습니다.
215 | 
216 | ```xaml
217 | <TextBlock Text="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=Content}"/>
218 | ```
219 | <br />
220 | 
221 | ### Static Property Binding
222 | 
223 | 바인딩 속성 값에 직접 접근할 수 있습니다.    
224 | 
225 | #### 1. `static` 속성을 선언합니다.
226 | 
227 | ```csharp
228 | namespace Exam
229 | {
230 |   public class ExamClass
231 |   {
232 |       public static string ExamText { get; set; }
233 |   }
234 | } 
235 | ```
236 | 
237 | #### 2. XAML에서 정적 클래스를 사용합니다.
238 | 
239 | ```xaml
240 | <Window ... xmlns:exam="clr-namespace:Exam">
241 | ```
242 | 
243 | #### 3. Binding property.
244 | 
245 | ```xaml
246 | <TextBlock Text="{Binding exam:ExamClass.ExamText}"/>
247 | ```
248 | 
249 | _또는 `Converter`를 사용하는 것처럼 리소스 키를 설정할 수 있습니다._  
250 | 
251 | ```xaml
252 | <Window.Resource>
253 |   <cvt:VisibilityToBooleanConverter x:Key="VisibilityToBooleanConverter"/>
254 |   <exam:ExamClass x:Key="ExamClass">
255 | </Window.Resource>
256 | ...
257 | 
258 | <TextBlock Text="{Binding Source={StaticResource ExamClass}, Path=ExamText}"/>
259 | ```
260 | 
261 | <br />
262 | 
263 | * * *  
264 | 
265 | ## Bad Binding & Good Binding 
266 | 
267 | #### :heavy_check_mark: 바인딩할 속성이 DataContext에 포함된 경우 ElementBinding을 사용할 필요가 없습니다.
268 | DataContext에 포함된 속성에 해대해 ElementBinding을 사용하는 것은 기능적으로 문제가 없지만, 바인딩의 기본 패턴을 깰 수 있습니다.
269 | 
270 | #### :slightly_frowning_face: Bad Binding 
271 | 
272 | ```xaml
273 | <TextBox x:Name="text" Text="{Binding UserName}"/>
274 | ...
275 | <TextBlock Text="{Binding ElementName=text, Path=Text}"/>
276 | ```
277 |    
278 | #### :grinning: Good Binding
279 | 
280 | ```xaml
281 | <TextBox Text="{Binding UserName}"/>
282 | ...
283 | <TextBlock Text="{Binding UserName}"/>
284 | ```
285 | 
286 | <br />
287 | 
288 | #### :heavy_check_mark: 상위 컨트롤의 속성을 사용할 때는 ElementBinding을 사용하지 마세요.    
289 | 
290 | #### :slightly_frowning_face: Bad Binding 
291 | 
292 | ```xaml
293 | <Window x:Name="win">
294 |   <TextBlock Text="{Binding ElementName=win, Path=DataContext.UserName}"/>
295 |   ...
296 | ```
297 |     
298 | #### :grinning: Good Binding
299 | 
300 | ```xaml
301 | <Window>
302 |   <TextBlock Text="{Binding RelativeSource={RelativeSource AncestorType=Window}, Path=DataContext.UserName}"/>
303 |   ...
304 | ```      
305 | 
306 | #### :laughing: Great!
307 | 
308 | ```xaml
309 | <Window>
310 |   <TextBlock DataContext="{Binding RelativeSource={RelativeSource AncestorType=Window}, Path=DataContext}" 
311 |              Text="{Binding UserName}"/>
312 |   ...
313 | ```
314 | <br />
315 | 
316 | #### :heavy_check_mark: 자기 자신의 속성을 사용할 때 ElementBinding을 사용하지 마세요.    
317 | 
318 | #### :slightly_frowning_face: Bad Binding 
319 | 
320 | ```xaml
321 | <TextBlock x:Name="txt" Text="{Binding ElementName=txt, Path=Foreground}"/>
322 | ```
323 | 
324 | #### :grinning: Good Binding
325 | 
326 | ```xaml
327 | <TextBlock Text="{Binding RelativeSource={RelativeSource Self}, Path=Foreground}"/>
328 | ```
329 | 
330 | <br>
331 | 
332 | ## Reference
333 | [:bookmark_tabs:](https://stackoverflow.com/questions/84278/how-do-i-use-wpf-bindings-with-relativesource) **StackOverflow** &nbsp; <ins>How do I use WPF bindings with RelativeSource?</ins>
334 | 


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