├── .gitignore
├── PluginDemo.Common
    ├── IPlugin.cs
    ├── PluginDemo.Common.csproj
    └── Properties
    │   └── AssemblyInfo.cs
├── PluginDemo.Host
    ├── AssemblyManager.cs
    ├── PluginDemo.Host.csproj
    ├── Program.cs
    ├── Properties
    │   └── AssemblyInfo.cs
    └── Scanner.cs
├── PluginDemo.sln
├── TestPluginOne
    ├── PluginOne.cs
    ├── Properties
    │   └── AssemblyInfo.cs
    └── TestPluginOne.csproj
└── readme.md


/.gitignore:
--------------------------------------------------------------------------------
 1 | obj
 2 | bin
 3 | *.ReSharper.user
 4 | _ReSharper.*
 5 | *.resharper
 6 | *.DotSettings.user
 7 | *.csproj.user
 8 | *.vbproj.user
 9 | *.suo
10 | *.cache


--------------------------------------------------------------------------------
/PluginDemo.Common/IPlugin.cs:
--------------------------------------------------------------------------------
 1 | namespace PluginDemo.Common
 2 | {
 3 |     public interface IPlugin
 4 |     {
 5 |         void Setup();
 6 |         void DoWork();
 7 |         void Teardown();
 8 |     }
 9 | }
10 | 


--------------------------------------------------------------------------------
/PluginDemo.Common/PluginDemo.Common.csproj:
--------------------------------------------------------------------------------
 1 | <?xml version="1.0" encoding="utf-8"?>
 2 | <Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
 3 |   <PropertyGroup>
 4 |     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
 5 |     <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
 6 |     <ProductVersion>9.0.30729</ProductVersion>
 7 |     <SchemaVersion>2.0</SchemaVersion>
 8 |     <ProjectGuid>{2DC4117F-CDBF-47D4-8F43-1771E57C3476}</ProjectGuid>
 9 |     <OutputType>Library</OutputType>
10 |     <AppDesignerFolder>Properties</AppDesignerFolder>
11 |     <RootNamespace>PluginDemo.Common</RootNamespace>
12 |     <AssemblyName>PluginDemo.Common</AssemblyName>
13 |     <TargetFrameworkVersion>v3.5</TargetFrameworkVersion>
14 |     <FileAlignment>512</FileAlignment>
15 |   </PropertyGroup>
16 |   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
17 |     <DebugSymbols>true</DebugSymbols>
18 |     <DebugType>full</DebugType>
19 |     <Optimize>false</Optimize>
20 |     <OutputPath>bin\Debug\</OutputPath>
21 |     <DefineConstants>DEBUG;TRACE</DefineConstants>
22 |     <ErrorReport>prompt</ErrorReport>
23 |     <WarningLevel>4</WarningLevel>
24 |   </PropertyGroup>
25 |   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
26 |     <DebugType>pdbonly</DebugType>
27 |     <Optimize>true</Optimize>
28 |     <OutputPath>bin\Release\</OutputPath>
29 |     <DefineConstants>TRACE</DefineConstants>
30 |     <ErrorReport>prompt</ErrorReport>
31 |     <WarningLevel>4</WarningLevel>
32 |   </PropertyGroup>
33 |   <ItemGroup>
34 |     <Reference Include="System" />
35 |     <Reference Include="System.Core">
36 |       <RequiredTargetFramework>3.5</RequiredTargetFramework>
37 |     </Reference>
38 |     <Reference Include="System.Xml.Linq">
39 |       <RequiredTargetFramework>3.5</RequiredTargetFramework>
40 |     </Reference>
41 |     <Reference Include="System.Data.DataSetExtensions">
42 |       <RequiredTargetFramework>3.5</RequiredTargetFramework>
43 |     </Reference>
44 |     <Reference Include="System.Data" />
45 |     <Reference Include="System.Xml" />
46 |   </ItemGroup>
47 |   <ItemGroup>
48 |     <Compile Include="IPlugin.cs" />
49 |     <Compile Include="Properties\AssemblyInfo.cs" />
50 |   </ItemGroup>
51 |   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
52 |   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
53 |        Other similar extension points exist, see Microsoft.Common.targets.
54 |   <Target Name="BeforeBuild">
55 |   </Target>
56 |   <Target Name="AfterBuild">
57 |   </Target>
58 |   -->
59 | </Project>


--------------------------------------------------------------------------------
/PluginDemo.Common/Properties/AssemblyInfo.cs:
--------------------------------------------------------------------------------
 1 | using System.Reflection;
 2 | using System.Runtime.CompilerServices;
 3 | using System.Runtime.InteropServices;
 4 | 
 5 | // General Information about an assembly is controlled through the following 
 6 | // set of attributes. Change these attribute values to modify the information
 7 | // associated with an assembly.
 8 | [assembly: AssemblyTitle("PluginDemo.Common")]
 9 | [assembly: AssemblyDescription("")]
10 | [assembly: AssemblyConfiguration("")]
11 | [assembly: AssemblyCompany("")]
12 | [assembly: AssemblyProduct("PluginDemo.Common")]
13 | [assembly: AssemblyCopyright("Copyright ©  2012")]
14 | [assembly: AssemblyTrademark("")]
15 | [assembly: AssemblyCulture("")]
16 | 
17 | // Setting ComVisible to false makes the types in this assembly not visible 
18 | // to COM components.  If you need to access a type in this assembly from 
19 | // COM, set the ComVisible attribute to true on that type.
20 | [assembly: ComVisible(false)]
21 | 
22 | // The following GUID is for the ID of the typelib if this project is exposed to COM
23 | [assembly: Guid("f7d7b116-1df3-45cb-8fbd-d30b8459fb17")]
24 | 
25 | // Version information for an assembly consists of the following four values:
26 | //
27 | //      Major Version
28 | //      Minor Version 
29 | //      Build Number
30 | //      Revision
31 | //
32 | // You can specify all the values or you can default the Build and Revision Numbers 
33 | // by using the '*' as shown below:
34 | // [assembly: AssemblyVersion("1.0.*")]
35 | [assembly: AssemblyVersion("1.0.0.0")]
36 | [assembly: AssemblyFileVersion("1.0.0.0")]
37 | 


--------------------------------------------------------------------------------
/PluginDemo.Host/AssemblyManager.cs:
--------------------------------------------------------------------------------
 1 | using System;
 2 | using System.IO;
 3 | using PluginDemo.Common;
 4 | 
 5 | namespace PluginDemo.Host
 6 | {
 7 |     internal class AssemblyManager
 8 |     {
 9 |         private AppDomain _domain;
10 |         private Scanner _scanner;
11 | 
12 |         public void LoadFrom(string path)
13 |         {
14 |             if (_domain != null)
15 |             {
16 |                 _scanner.Teardown();
17 |                 AppDomain.Unload(_domain);
18 |             }
19 | 
20 |             var name = Path.GetFileNameWithoutExtension(path);
21 |             var dirPath = Path.GetFullPath(Path.GetDirectoryName(path));
22 | 
23 |             var setup = new AppDomainSetup
24 |             {
25 |                 ApplicationBase = AppDomain.CurrentDomain.BaseDirectory,
26 |                 PrivateBinPath = dirPath,
27 |                 ShadowCopyFiles = "true",
28 |                 ShadowCopyDirectories = dirPath,
29 |             };
30 | 
31 |             _domain = AppDomain.CreateDomain(name + "Domain", AppDomain.CurrentDomain.Evidence, setup);
32 | 
33 |             var scannerType = typeof (Scanner);
34 |             _scanner = (Scanner)_domain.CreateInstanceAndUnwrap(scannerType.Assembly.FullName, scannerType.FullName);
35 |             _scanner.Load(name);
36 |             _scanner.Setup();
37 | 
38 |         }
39 | 
40 |         public void DoWork()
41 |         {
42 |             _scanner.DoWork();
43 |         }
44 | 
45 |         public IPlugin ShowCrossDomainPollutionExceptions()
46 |         {
47 |             return _scanner.ShowCrossDomainPollutionExceptions();
48 |         }
49 |     }
50 | }


--------------------------------------------------------------------------------
/PluginDemo.Host/PluginDemo.Host.csproj:
--------------------------------------------------------------------------------
 1 | <?xml version="1.0" encoding="utf-8"?>
 2 | <Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
 3 |   <PropertyGroup>
 4 |     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
 5 |     <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
 6 |     <ProductVersion>9.0.30729</ProductVersion>
 7 |     <SchemaVersion>2.0</SchemaVersion>
 8 |     <ProjectGuid>{31BB4879-9F60-4418-8320-51AA171AFA1C}</ProjectGuid>
 9 |     <OutputType>Exe</OutputType>
10 |     <AppDesignerFolder>Properties</AppDesignerFolder>
11 |     <RootNamespace>PluginDemo.Host</RootNamespace>
12 |     <AssemblyName>PluginDemo.Host</AssemblyName>
13 |     <TargetFrameworkVersion>v3.5</TargetFrameworkVersion>
14 |     <FileAlignment>512</FileAlignment>
15 |   </PropertyGroup>
16 |   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
17 |     <DebugSymbols>true</DebugSymbols>
18 |     <DebugType>full</DebugType>
19 |     <Optimize>false</Optimize>
20 |     <OutputPath>..\bin\</OutputPath>
21 |     <DefineConstants>DEBUG;TRACE</DefineConstants>
22 |     <ErrorReport>prompt</ErrorReport>
23 |     <WarningLevel>4</WarningLevel>
24 |   </PropertyGroup>
25 |   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
26 |     <DebugType>pdbonly</DebugType>
27 |     <Optimize>true</Optimize>
28 |     <OutputPath>..\bin\</OutputPath>
29 |     <DefineConstants>TRACE</DefineConstants>
30 |     <ErrorReport>prompt</ErrorReport>
31 |     <WarningLevel>4</WarningLevel>
32 |   </PropertyGroup>
33 |   <ItemGroup>
34 |     <Reference Include="System" />
35 |     <Reference Include="System.Core">
36 |       <RequiredTargetFramework>3.5</RequiredTargetFramework>
37 |     </Reference>
38 |     <Reference Include="System.Xml.Linq">
39 |       <RequiredTargetFramework>3.5</RequiredTargetFramework>
40 |     </Reference>
41 |     <Reference Include="System.Data.DataSetExtensions">
42 |       <RequiredTargetFramework>3.5</RequiredTargetFramework>
43 |     </Reference>
44 |     <Reference Include="System.Data" />
45 |     <Reference Include="System.Xml" />
46 |   </ItemGroup>
47 |   <ItemGroup>
48 |     <Compile Include="AssemblyManager.cs" />
49 |     <Compile Include="Program.cs" />
50 |     <Compile Include="Properties\AssemblyInfo.cs" />
51 |     <Compile Include="Scanner.cs" />
52 |   </ItemGroup>
53 |   <ItemGroup>
54 |     <ProjectReference Include="..\PluginDemo.Common\PluginDemo.Common.csproj">
55 |       <Project>{2DC4117F-CDBF-47D4-8F43-1771E57C3476}</Project>
56 |       <Name>PluginDemo.Common</Name>
57 |     </ProjectReference>
58 |   </ItemGroup>
59 |   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
60 |   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
61 |        Other similar extension points exist, see Microsoft.Common.targets.
62 |   <Target Name="BeforeBuild">
63 |   </Target>
64 |   <Target Name="AfterBuild">
65 |   </Target>
66 |   -->
67 | </Project>


--------------------------------------------------------------------------------
/PluginDemo.Host/Program.cs:
--------------------------------------------------------------------------------
 1 | using System;
 2 | using System.IO;
 3 | 
 4 | namespace PluginDemo.Host
 5 | {
 6 |     class Program
 7 |     {
 8 |         static void Main(string[] args)
 9 |         {
10 |             Directory.CreateDirectory("plugins");
11 | 
12 |             var manager = new AssemblyManager();
13 | 
14 |             manager.LoadFrom("plugins\\TestPluginOne.dll");
15 |             manager.DoWork();
16 | 
17 |            Directory.Delete("plugins", true);
18 | 
19 |             manager.DoWork();
20 |             manager.ShowCrossDomainPolutionExceptions();
21 | 
22 |             Console.WriteLine("Press any key to continue...");
23 |             Console.ReadKey();
24 |         }
25 |     }
26 | }
27 | 


--------------------------------------------------------------------------------
/PluginDemo.Host/Properties/AssemblyInfo.cs:
--------------------------------------------------------------------------------
 1 | using System.Reflection;
 2 | using System.Runtime.CompilerServices;
 3 | using System.Runtime.InteropServices;
 4 | 
 5 | // General Information about an assembly is controlled through the following 
 6 | // set of attributes. Change these attribute values to modify the information
 7 | // associated with an assembly.
 8 | [assembly: AssemblyTitle("PluginDemo.Host")]
 9 | [assembly: AssemblyDescription("")]
10 | [assembly: AssemblyConfiguration("")]
11 | [assembly: AssemblyCompany("")]
12 | [assembly: AssemblyProduct("PluginDemo.Host")]
13 | [assembly: AssemblyCopyright("Copyright ©  2012")]
14 | [assembly: AssemblyTrademark("")]
15 | [assembly: AssemblyCulture("")]
16 | 
17 | // Setting ComVisible to false makes the types in this assembly not visible 
18 | // to COM components.  If you need to access a type in this assembly from 
19 | // COM, set the ComVisible attribute to true on that type.
20 | [assembly: ComVisible(false)]
21 | 
22 | // The following GUID is for the ID of the typelib if this project is exposed to COM
23 | [assembly: Guid("1cbd52c9-cfad-4b68-8ea0-cfe564c76d1f")]
24 | 
25 | // Version information for an assembly consists of the following four values:
26 | //
27 | //      Major Version
28 | //      Minor Version 
29 | //      Build Number
30 | //      Revision
31 | //
32 | // You can specify all the values or you can default the Build and Revision Numbers 
33 | // by using the '*' as shown below:
34 | // [assembly: AssemblyVersion("1.0.*")]
35 | [assembly: AssemblyVersion("1.0.0.0")]
36 | [assembly: AssemblyFileVersion("1.0.0.0")]
37 | 


--------------------------------------------------------------------------------
/PluginDemo.Host/Scanner.cs:
--------------------------------------------------------------------------------
 1 | using System;
 2 | using System.Collections.Generic;
 3 | using System.Linq;
 4 | using System.Reflection;
 5 | using PluginDemo.Common;
 6 | 
 7 | namespace PluginDemo.Host
 8 | {
 9 |     [Serializable]
10 |     internal class Scanner : MarshalByRefObject
11 |     {
12 |         private readonly List<IPlugin> _plugins;
13 | 
14 |         public Scanner()
15 |         {
16 |             _plugins = new List<IPlugin>();
17 |            
18 | 
19 |         }
20 | 
21 |         private void GetAllPlugins(AppDomain domain)
22 |         {
23 |             var pluginType = typeof (IPlugin);
24 | 
25 |             var types = domain.GetAssemblies()
26 |                               .SelectMany(a => a.GetTypes())
27 |                               .Where(t => t.GetInterface(pluginType.Name) != null);
28 | 
29 |             var ctors = types.Select(t => t.GetConstructor(new Type[] {}))
30 |                              .Where(c => c != null);
31 | 
32 |             _plugins.Clear();
33 |             _plugins.AddRange(ctors.Select(c => c.Invoke(null))
34 |                                    .Cast<IPlugin>());
35 |         }
36 | 
37 |         public void Setup()
38 |         {
39 |             GetAllPlugins(AppDomain.CurrentDomain);
40 |             _plugins.ForEach(p => p.Setup());
41 |         }
42 | 
43 |         public void DoWork()
44 |         {
45 |             _plugins.ForEach(p => p.DoWork());
46 |         }
47 | 
48 |         public void Teardown()
49 |         {
50 |             _plugins.ForEach(p => p.Teardown());
51 |         }
52 | 
53 |         public void Load(string name)
54 |         {
55 |             Assembly.Load(name);
56 |         }
57 | 
58 |         public IPlugin ShowCrossDomainPollutionExceptions()
59 |         {
60 |             return _plugins.First();
61 |         }
62 |     }
63 | }


--------------------------------------------------------------------------------
/PluginDemo.sln:
--------------------------------------------------------------------------------
 1 | 
 2 | Microsoft Visual Studio Solution File, Format Version 10.00
 3 | # Visual Studio 2008
 4 | Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "PluginDemo.Common", "PluginDemo.Common\PluginDemo.Common.csproj", "{2DC4117F-CDBF-47D4-8F43-1771E57C3476}"
 5 | EndProject
 6 | Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TestPluginOne", "TestPluginOne\TestPluginOne.csproj", "{343C0D11-BDE1-4FE5-9BFD-3A3DAE3DAE0A}"
 7 | EndProject
 8 | Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "PluginDemo.Host", "PluginDemo.Host\PluginDemo.Host.csproj", "{31BB4879-9F60-4418-8320-51AA171AFA1C}"
 9 | EndProject
10 | Global
11 | 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
12 | 		Debug|Any CPU = Debug|Any CPU
13 | 		Release|Any CPU = Release|Any CPU
14 | 	EndGlobalSection
15 | 	GlobalSection(ProjectConfigurationPlatforms) = postSolution
16 | 		{2DC4117F-CDBF-47D4-8F43-1771E57C3476}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
17 | 		{2DC4117F-CDBF-47D4-8F43-1771E57C3476}.Debug|Any CPU.Build.0 = Debug|Any CPU
18 | 		{2DC4117F-CDBF-47D4-8F43-1771E57C3476}.Release|Any CPU.ActiveCfg = Release|Any CPU
19 | 		{2DC4117F-CDBF-47D4-8F43-1771E57C3476}.Release|Any CPU.Build.0 = Release|Any CPU
20 | 		{343C0D11-BDE1-4FE5-9BFD-3A3DAE3DAE0A}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
21 | 		{343C0D11-BDE1-4FE5-9BFD-3A3DAE3DAE0A}.Debug|Any CPU.Build.0 = Debug|Any CPU
22 | 		{343C0D11-BDE1-4FE5-9BFD-3A3DAE3DAE0A}.Release|Any CPU.ActiveCfg = Release|Any CPU
23 | 		{343C0D11-BDE1-4FE5-9BFD-3A3DAE3DAE0A}.Release|Any CPU.Build.0 = Release|Any CPU
24 | 		{31BB4879-9F60-4418-8320-51AA171AFA1C}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
25 | 		{31BB4879-9F60-4418-8320-51AA171AFA1C}.Debug|Any CPU.Build.0 = Debug|Any CPU
26 | 		{31BB4879-9F60-4418-8320-51AA171AFA1C}.Release|Any CPU.ActiveCfg = Release|Any CPU
27 | 		{31BB4879-9F60-4418-8320-51AA171AFA1C}.Release|Any CPU.Build.0 = Release|Any CPU
28 | 	EndGlobalSection
29 | 	GlobalSection(SolutionProperties) = preSolution
30 | 		HideSolutionNode = FALSE
31 | 	EndGlobalSection
32 | EndGlobal
33 | 


--------------------------------------------------------------------------------
/TestPluginOne/PluginOne.cs:
--------------------------------------------------------------------------------
 1 | using System;
 2 | using PluginDemo.Common;
 3 | 
 4 | namespace TestPluginOne
 5 | {
 6 |     public class PluginOne : IPlugin
 7 |     {
 8 |         public void Setup()
 9 |         {
10 |             Console.WriteLine("PluginOne.Setup");
11 |         }
12 | 
13 |         public void DoWork()
14 |         {
15 |             Console.WriteLine("PluginOne.DoWork");
16 |         }
17 | 
18 |         public void Teardown()
19 |         {
20 |             Console.WriteLine("PluginOne.Teardown");
21 |         }
22 |     }
23 | }
24 | 


--------------------------------------------------------------------------------
/TestPluginOne/Properties/AssemblyInfo.cs:
--------------------------------------------------------------------------------
 1 | using System.Reflection;
 2 | using System.Runtime.CompilerServices;
 3 | using System.Runtime.InteropServices;
 4 | 
 5 | // General Information about an assembly is controlled through the following 
 6 | // set of attributes. Change these attribute values to modify the information
 7 | // associated with an assembly.
 8 | [assembly: AssemblyTitle("TestPlugin")]
 9 | [assembly: AssemblyDescription("")]
10 | [assembly: AssemblyConfiguration("")]
11 | [assembly: AssemblyCompany("")]
12 | [assembly: AssemblyProduct("TestPlugin")]
13 | [assembly: AssemblyCopyright("Copyright ©  2012")]
14 | [assembly: AssemblyTrademark("")]
15 | [assembly: AssemblyCulture("")]
16 | 
17 | // Setting ComVisible to false makes the types in this assembly not visible 
18 | // to COM components.  If you need to access a type in this assembly from 
19 | // COM, set the ComVisible attribute to true on that type.
20 | [assembly: ComVisible(false)]
21 | 
22 | // The following GUID is for the ID of the typelib if this project is exposed to COM
23 | [assembly: Guid("b7a839ef-f8f9-44d2-9b5f-e92b3c96cf2c")]
24 | 
25 | // Version information for an assembly consists of the following four values:
26 | //
27 | //      Major Version
28 | //      Minor Version 
29 | //      Build Number
30 | //      Revision
31 | //
32 | // You can specify all the values or you can default the Build and Revision Numbers 
33 | // by using the '*' as shown below:
34 | // [assembly: AssemblyVersion("1.0.*")]
35 | [assembly: AssemblyVersion("1.0.0.0")]
36 | [assembly: AssemblyFileVersion("1.0.0.0")]
37 | 


--------------------------------------------------------------------------------
/TestPluginOne/TestPluginOne.csproj:
--------------------------------------------------------------------------------
 1 | <?xml version="1.0" encoding="utf-8"?>
 2 | <Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
 3 |   <PropertyGroup>
 4 |     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
 5 |     <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
 6 |     <ProductVersion>9.0.30729</ProductVersion>
 7 |     <SchemaVersion>2.0</SchemaVersion>
 8 |     <ProjectGuid>{343C0D11-BDE1-4FE5-9BFD-3A3DAE3DAE0A}</ProjectGuid>
 9 |     <OutputType>Library</OutputType>
10 |     <AppDesignerFolder>Properties</AppDesignerFolder>
11 |     <RootNamespace>TestPluginOne</RootNamespace>
12 |     <AssemblyName>TestPluginOne</AssemblyName>
13 |     <TargetFrameworkVersion>v3.5</TargetFrameworkVersion>
14 |     <FileAlignment>512</FileAlignment>
15 |   </PropertyGroup>
16 |   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
17 |     <DebugSymbols>true</DebugSymbols>
18 |     <DebugType>full</DebugType>
19 |     <Optimize>false</Optimize>
20 |     <OutputPath>..\bin\plugins\</OutputPath>
21 |     <DefineConstants>DEBUG;TRACE</DefineConstants>
22 |     <ErrorReport>prompt</ErrorReport>
23 |     <WarningLevel>4</WarningLevel>
24 |   </PropertyGroup>
25 |   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
26 |     <DebugType>pdbonly</DebugType>
27 |     <Optimize>true</Optimize>
28 |     <OutputPath>..\bin\plugins\</OutputPath>
29 |     <DefineConstants>TRACE</DefineConstants>
30 |     <ErrorReport>prompt</ErrorReport>
31 |     <WarningLevel>4</WarningLevel>
32 |   </PropertyGroup>
33 |   <ItemGroup>
34 |     <Reference Include="System" />
35 |     <Reference Include="System.Core">
36 |       <RequiredTargetFramework>3.5</RequiredTargetFramework>
37 |     </Reference>
38 |     <Reference Include="System.Xml.Linq">
39 |       <RequiredTargetFramework>3.5</RequiredTargetFramework>
40 |     </Reference>
41 |     <Reference Include="System.Data.DataSetExtensions">
42 |       <RequiredTargetFramework>3.5</RequiredTargetFramework>
43 |     </Reference>
44 |     <Reference Include="System.Data" />
45 |     <Reference Include="System.Xml" />
46 |   </ItemGroup>
47 |   <ItemGroup>
48 |     <Compile Include="PluginOne.cs" />
49 |     <Compile Include="Properties\AssemblyInfo.cs" />
50 |   </ItemGroup>
51 |   <ItemGroup>
52 |     <ProjectReference Include="..\PluginDemo.Common\PluginDemo.Common.csproj">
53 |       <Project>{2DC4117F-CDBF-47D4-8F43-1771E57C3476}</Project>
54 |       <Name>PluginDemo.Common</Name>
55 |       <Private>False</Private>
56 |     </ProjectReference>
57 |   </ItemGroup>
58 |   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
59 |   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
60 |        Other similar extension points exist, see Microsoft.Common.targets.
61 |   <Target Name="BeforeBuild">
62 |   </Target>
63 |   <Target Name="AfterBuild">
64 |   </Target>
65 |   -->
66 | </Project>


--------------------------------------------------------------------------------
/readme.md:
--------------------------------------------------------------------------------
 1 | 
 2 | This is mostly in response to this [StackOverflow Question][2], and partly because I always forget some of the details on using Shadow Copy.
 3 | 
 4 | Obviously this would need a lot more error checking etc, but should be a good starting point.
 5 | 
 6 | If you are writing a plugin framework for your application, I recommend looking into an existing framework for it such as MEF, rather than rolling your own.
 7 | 
 8 | PluginDemo.Common
 9 | ---
10 | 
11 | This contains all your common code for plugins - pretty much what you would distribute as your app's SDK.
12 | In this case, we just have one interface called IPlugin, which we use for finding our plugin's types.
13 | 
14 | TestPluginOne
15 | ---
16 | 
17 | This is your plugin - note the reference to PluginDemo.Common is `CopyLocal = false` - we don't need a copy of it as we have our own version in the host.
18 | 
19 | PluginDemo.Host
20 | ---
21 | 
22 | This is your main application - note it only has a reference to PluginDemo.Common, not to TestPluginOne.
23 | Points of interest here are:
24 | * Scanner:
25 |     - This must inherit from `MarshalByRefObject`, as it will be marshalled across AppDomains (our application's domain, and the ones we create for our plugins.)
26 |     - You must not polute your main AppDomain with types from the plugins - if a method in `Scanner` returns a `Type` that is not available in your AppDomain, you will get an `FileNotFoundException`, with the name of the assembly which the type came from.  This is what `Scanner.ShowCrossDomainPolutionExceptions` demonstrates.
27 |     - If you are going to have plugins which live for a long time (greater than 5mins, if I remember correctly), then change the `Scanner` to inherit from the classes in this question on [StackOverflow][1], as otherwise you will run into `System.Runtime.Remoting.RemotingException: Object [...] has been disconnected or does not exist at the server.` exceptions.
28 | 
29 | * AssemblyManager:
30 |     - To prevent file locking on our plugins we use *Shadow Copying*.
31 |     - This will currently leave debris in your temp folder, so don't forget to clear your AppDomain's `CachePath` after unloading it.  You can also set your own `CachePath` to your own location if you prefer.
32 |     - To allow us to communicate across AppDomains, we create an instance of `Scanner` using `AppDomain.CreateInstanceAndUnwrap`.  This creates an instance of the `Scanner` class in the new AppDomain, and returns a proxy to it, which is stored in the current AppDomain (in the `_scanner` field in this case.)  You can see this by setting a break point on the line and inspecting _scanner (it will be a `__TransparentProxy` type.)
33 | 
34 | * Program:
35 |     - Uses the `AssemblyManager` to load `TestPluginOne`.
36 |     - Calls a method on a type in `TestPluginOne`.
37 |     - Deletes the `TestPluginOne` loaded from.
38 |     - Calls the same method in `TestPluginOne` (showing that we are not using the local copy of the dll).
39 |     - Calls the Cross Domain Pollution test method.
40 | 
41 | [1]: http://stackoverflow.com/questions/2410221/appdomain-and-marshalbyrefobject-life-time-how-to-avoid-remotingexception
42 | [2]: http://stackoverflow.com/questions/1031431/system-reflection-assembly-loadfile-locks-file/1031449#1031449


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