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FieldBuilder.SetCustomAttribute Metodo

  • Riferimento

Definizione

Spazio dei nomi:
System.Reflection.Emit
Assembly:
System.Reflection.Emit.dll
Assembly:
mscorlib.dll
Assembly:
netstandard.dll
Pacchetto:
System.Reflection.Emit v4.7.0

Imposta un attributo personalizzato.

Overload

SetCustomAttribute(CustomAttributeBuilder)

Imposta un attributo personalizzato usando un generatore di attributi personalizzati.
SetCustomAttribute(ConstructorInfo, Byte[])

Imposta un attributo personalizzato usando un BLOB di attributi personalizzati specificato.

SetCustomAttribute(CustomAttributeBuilder)

Origine:
FieldBuilder.cs
Origine:
FieldBuilder.cs
Origine:
FieldBuilder.cs

Imposta un attributo personalizzato usando un generatore di attributi personalizzati.

public:
 void SetCustomAttribute(System::Reflection::Emit::CustomAttributeBuilder ^ customBuilder);
public void SetCustomAttribute (System.Reflection.Emit.CustomAttributeBuilder customBuilder);
member this.SetCustomAttribute : System.Reflection.Emit.CustomAttributeBuilder -> unit
Public Sub SetCustomAttribute (customBuilder As CustomAttributeBuilder)

Parametri

customBuilder
CustomAttributeBuilder

Un'istanza di una classe helper per definire l'attributo personalizzato.

Eccezioni

ArgumentNullException

con è null.

InvalidOperationException

Il tipo padre del campo è completo.

Esempio

Nell'esempio di codice seguente viene illustrato l'uso di SetCustomAttribute nel contesto di FieldBuilder, usando un CustomAttributeBuilderoggetto .

using namespace System;
using namespace System::Threading;
using namespace System::Reflection;
using namespace System::Reflection::Emit;

[AttributeUsage(AttributeTargets::All,AllowMultiple=false)]
public ref class MyAttribute1: public Attribute
{
public:
   String^ myCustomAttributeValue;
   MyAttribute1( String^ myString )
   {
      myCustomAttributeValue = myString;
   }
};


[AttributeUsage(AttributeTargets::All,AllowMultiple=false)]
public ref class MyAttribute2: public Attribute
{
public:
   bool myCustomAttributeValue;
   MyAttribute2( bool myBool )
   {
      myCustomAttributeValue = myBool;
   }
};

Type^ CreateCallee( AppDomain^ currentDomain )
{
   // Create a simple name for the assembly.
   AssemblyName^ myAssemblyName = gcnew AssemblyName;
   myAssemblyName->Name = "EmittedAssembly";

   // Create the called dynamic assembly.
   AssemblyBuilder^ myAssemblyBuilder = currentDomain->DefineDynamicAssembly( myAssemblyName, AssemblyBuilderAccess::RunAndSave );
   ModuleBuilder^ myModuleBuilder = myAssemblyBuilder->DefineDynamicModule( "EmittedModule", "EmittedModule.mod" );

   // Define a public class named 'CustomClass' in the assembly.
   TypeBuilder^ myTypeBuilder = myModuleBuilder->DefineType( "CustomClass", TypeAttributes::Public );

   // Define a private String field named 'MyField' in the type.
   FieldBuilder^ myFieldBuilder = myTypeBuilder->DefineField( "MyField", String::typeid, FieldAttributes::Public );
   Type^ myAttributeType1 = MyAttribute1::typeid;

   // Create a Constructorinfo Object* for attribute 'MyAttribute1'.
   array<Type^>^type1 = {String::typeid};
   ConstructorInfo^ myConstructorInfo = myAttributeType1->GetConstructor( type1 );

   // Create the CustomAttribute instance of attribute of type 'MyAttribute1'.
   array<Object^>^obj1 = {"Test"};
   CustomAttributeBuilder^ attributeBuilder = gcnew CustomAttributeBuilder( myConstructorInfo,obj1 );

   // Set the CustomAttribute 'MyAttribute1' to the Field.
   myFieldBuilder->SetCustomAttribute( attributeBuilder );
   Type^ myAttributeType2 = MyAttribute2::typeid;

   // Create a Constructorinfo Object* for attribute 'MyAttribute2'.
   array<Type^>^type2 = {bool::typeid};
   ConstructorInfo^ myConstructorInfo2 = myAttributeType2->GetConstructor( type2 );

   // Set the CustomAttribute 'MyAttribute2' to the Field.
   array<Byte>^bytes = {01,00,01,00,00};
   myFieldBuilder->SetCustomAttribute( myConstructorInfo2, bytes );

   // Create a method.
   array<Type^>^type3 = {String::typeid,int::typeid};
   MethodBuilder^ myMethodBuilder = myTypeBuilder->DefineMethod( "MyMethod", MethodAttributes::Public, nullptr, type3 );
   ILGenerator^ myILGenerator = myMethodBuilder->GetILGenerator();
   myILGenerator->Emit( OpCodes::Ldarg_0 );
   myILGenerator->Emit( OpCodes::Ldarg_1 );
   myILGenerator->Emit( OpCodes::Stfld, myFieldBuilder );
   myILGenerator->EmitWriteLine( "Value of the Field is :" );
   myILGenerator->EmitWriteLine( myFieldBuilder );
   myILGenerator->Emit( OpCodes::Ret );
   return myTypeBuilder->CreateType();
}

int main()
{
   try
   {
      Type^ myCustomClass = CreateCallee( Thread::GetDomain() );

      // Construct an instance of a type.
      Object^ myObject = Activator::CreateInstance( myCustomClass );
      Console::WriteLine( "FieldBuilder Sample" );

      // Find a method in this type and call it on this Object*.
      MethodInfo^ myMethodInfo = myCustomClass->GetMethod( "MyMethod" );
      array<Object^>^obj1 = {"Sample string",3};
      myMethodInfo->Invoke( myObject, obj1 );

      // Retrieve the values of Attributes applied to field and display to console.
      array<FieldInfo^>^myFieldInfo = myCustomClass->GetFields();
      for ( int i = 0; i < myFieldInfo->Length; i++ )
      {
         array<Object^>^attributes = myFieldInfo[ i ]->GetCustomAttributes( true );
         for ( int index = 0; index < attributes->Length; index++ )
         {
            if ( dynamic_cast<MyAttribute1^>(attributes[ index ]) )
            {
               MyAttribute1^ myCustomAttribute = safe_cast<MyAttribute1^>(attributes[ index ]);
               Console::WriteLine( "Attribute Value of (MyAttribute1): {0}", myCustomAttribute->myCustomAttributeValue );
            }
            if ( dynamic_cast<MyAttribute2^>(attributes[ index ]) )
            {
               MyAttribute2^ myCustomAttribute = safe_cast<MyAttribute2^>(attributes[ index ]);
               Console::WriteLine( "Attribute Value of (MyAttribute2): {0}", myCustomAttribute->myCustomAttributeValue );
            }
         }
      }
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( "Exception Caught {0}", e->Message );
   }
}


using System;
using System.Threading;
using System.Reflection;
using System.Reflection.Emit;

namespace MySample
{
   [AttributeUsage(AttributeTargets.All, AllowMultiple = false)]
   public class MyAttribute1 :Attribute
   {
      public string myCustomAttributeValue;
      public MyAttribute1(string myString)
      {
         myCustomAttributeValue = myString;
      }
   }
   [AttributeUsage(AttributeTargets.All, AllowMultiple = false)]
   public class MyAttribute2 :Attribute
   {
      public bool myCustomAttributeValue;
      public MyAttribute2(bool myBool)
      {
         myCustomAttributeValue = myBool;
      }
   }

   class FieldBuilder_Sample
   {
      private static Type CreateCallee(AppDomain currentDomain)
      {

         // Create a simple name for the assembly.
         AssemblyName myAssemblyName = new AssemblyName();
         myAssemblyName.Name = "EmittedAssembly";
         // Create the called dynamic assembly.
         AssemblyBuilder myAssemblyBuilder =
            currentDomain.DefineDynamicAssembly(myAssemblyName, AssemblyBuilderAccess.RunAndSave);
         ModuleBuilder myModuleBuilder =
                  myAssemblyBuilder.DefineDynamicModule("EmittedModule","EmittedModule.mod");
         // Define a public class named 'CustomClass' in the assembly.
         TypeBuilder myTypeBuilder = myModuleBuilder.DefineType("CustomClass",
            TypeAttributes.Public);
         // Define a private String field named 'MyField' in the type.
         FieldBuilder myFieldBuilder =
            myTypeBuilder.DefineField("MyField", typeof(String), FieldAttributes.Public);
         Type myAttributeType1 = typeof(MyAttribute1);
         // Create a Constructorinfo object for attribute 'MyAttribute1'.
         ConstructorInfo myConstructorInfo = myAttributeType1.GetConstructor(
            new Type[1]{typeof(string)});
         // Create the CustomAttribute instance of attribute of type 'MyAttribute1'.
         CustomAttributeBuilder attributeBuilder =
                     new CustomAttributeBuilder( myConstructorInfo,new object[1]{"Test"});
         // Set the CustomAttribute 'MyAttribute1' to the Field.
         myFieldBuilder.SetCustomAttribute(attributeBuilder);

          Type myAttributeType2 = typeof(MyAttribute2);
         // Create a Constructorinfo object for attribute 'MyAttribute2'.
        ConstructorInfo myConstructorInfo2 = myAttributeType2.GetConstructor(
            new Type[1]{typeof(bool)});
         // Set the CustomAttribute 'MyAttribute2' to the Field.
         myFieldBuilder.SetCustomAttribute(myConstructorInfo2,new byte[]{01,00,01,00,00});

         // Create a method.
         MethodBuilder myMethodBuilder= myTypeBuilder.DefineMethod("MyMethod",
            MethodAttributes.Public,null,new Type[2]{typeof(string),typeof(int)});

         ILGenerator myILGenerator = myMethodBuilder.GetILGenerator();
         myILGenerator.Emit(OpCodes.Ldarg_0);
         myILGenerator.Emit(OpCodes.Ldarg_1);
         myILGenerator.Emit(OpCodes.Stfld, myFieldBuilder);
         myILGenerator.EmitWriteLine("Value of the Field is :");
         myILGenerator.EmitWriteLine(myFieldBuilder);
         myILGenerator.Emit(OpCodes.Ret);

         return myTypeBuilder.CreateType();
      }
      public static void Main()
      {
         try
         {
            Type myCustomClass = CreateCallee(Thread.GetDomain());
            // Construct an instance of a type.
            Object myObject = Activator.CreateInstance(myCustomClass);
            Console.WriteLine( "FieldBuilder Sample");
            // Find a method in this type and call it on this object.
            MethodInfo myMethodInfo = myCustomClass.GetMethod("MyMethod");
            myMethodInfo.Invoke(myObject, new object[2]{"Sample string",3});
            // Retrieve the values of Attributes applied to field and display to console.
            FieldInfo[] myFieldInfo = myCustomClass.GetFields();
            for(int i =0;i<myFieldInfo.Length;i++)
            {
               object[] attributes = myFieldInfo[i].GetCustomAttributes(true);
               for(int index=0; index < attributes.Length; index++)
               {
                  if(attributes[index] is MyAttribute1)
                  {
                     MyAttribute1 myCustomAttribute = (MyAttribute1)attributes[index];
                     Console.WriteLine("Attribute Value of (MyAttribute1): "
                                       + myCustomAttribute.myCustomAttributeValue);
                  }
                  if(attributes[index] is MyAttribute2)
                  {
                     MyAttribute2 myCustomAttribute = (MyAttribute2)attributes[index];
                     Console.WriteLine("Attribute Value of (MyAttribute2): "
                                       + myCustomAttribute.myCustomAttributeValue);
                  }
               }
            }
         }
         catch (Exception e)
         {
            Console.WriteLine("Exception Caught "+e.Message);
         }
      }
   }
}

Imports System.Threading
Imports System.Reflection
Imports System.Reflection.Emit

Namespace MySample
   <AttributeUsage(AttributeTargets.All, AllowMultiple:=False)> Public Class MyAttribute1
      Inherits Attribute
      Public myCustomAttributeValue As String

      Public Sub New(ByVal myString As String)
         myCustomAttributeValue = myString
      End Sub
   End Class
   <AttributeUsage(AttributeTargets.All, AllowMultiple:=False)> Public Class MyAttribute2
      Inherits Attribute
      Public myCustomAttributeValue As Boolean

      Public Sub New(ByVal myBool As Boolean)
         myCustomAttributeValue = myBool
      End Sub
   End Class

   Class FieldBuilder_Sample

      Private Shared Function CreateCallee(ByVal currentDomain As AppDomain) As Type
         ' Create a simple name for the assembly.
         Dim myAssemblyName As New AssemblyName()
         myAssemblyName.Name = "EmittedAssembly"
         ' Create the called dynamic assembly.
         Dim myAssemblyBuilder As AssemblyBuilder = _
                     currentDomain.DefineDynamicAssembly(myAssemblyName, _
                     AssemblyBuilderAccess.RunAndSave)
         Dim myModuleBuilder As ModuleBuilder = _
               myAssemblyBuilder.DefineDynamicModule("EmittedModule", _
                                                   "EmittedModule.mod")
         ' Define a public class named 'CustomClass' in the assembly.
         Dim myTypeBuilder As TypeBuilder = myModuleBuilder.DefineType("CustomClass", _
                                                TypeAttributes.Public)
         ' Define a private String field named 'MyField' in the type.
         Dim myFieldBuilder As FieldBuilder = myTypeBuilder.DefineField("MyField", _
                                       GetType(String), FieldAttributes.Public)
         Dim myAttributeType1 As Type = GetType(MyAttribute1)
         ' Create a Constructorinfo object for attribute 'MyAttribute1'.
         Dim myConstructorInfo As ConstructorInfo = _
                     myAttributeType1.GetConstructor(New Type(0) {GetType(String)})
         ' Create the CustomAttribute instance of attribute of type 'MyAttribute1'.
         Dim attributeBuilder As _
         New CustomAttributeBuilder(myConstructorInfo, New Object(0) {"Test"})
         ' Set the CustomAttribute 'MyAttribute1' to the Field.
         myFieldBuilder.SetCustomAttribute(attributeBuilder)

         Dim myAttributeType2 As Type = GetType(MyAttribute2)
         ' Create a Constructorinfo object for attribute 'MyAttribute2'.
         Dim myConstructorInfo2 As ConstructorInfo = _
                  myAttributeType2.GetConstructor(New Type(0) {GetType(Boolean)})
         ' Set the CustomAttribute 'MyAttribute2' to the Field.
         myFieldBuilder.SetCustomAttribute(myConstructorInfo2, New Byte() {1, 0, 1, 0, 0})

         ' Create a method.
         Dim myMethodBuilder As MethodBuilder = myTypeBuilder.DefineMethod("MyMethod", _
               MethodAttributes.Public, Nothing, New Type(1) {GetType(String), GetType(Integer)})
         Dim myILGenerator As ILGenerator = myMethodBuilder.GetILGenerator()
         myILGenerator.Emit(OpCodes.Ldarg_0)
         myILGenerator.Emit(OpCodes.Ldarg_1)
         myILGenerator.Emit(OpCodes.Stfld, myFieldBuilder)
         myILGenerator.EmitWriteLine("Value of the Field is :")
         myILGenerator.EmitWriteLine(myFieldBuilder)
         myILGenerator.Emit(OpCodes.Ret)

         Return myTypeBuilder.CreateType()
      End Function 'CreateCallee

      Public Shared Sub Main()
         Try
            Dim myCustomClass As Type = CreateCallee(Thread.GetDomain())
            ' Construct an instance of a type.
            Dim myObject As Object = Activator.CreateInstance(myCustomClass)
            Console.WriteLine("FieldBuilder Sample")
            ' Find a method in this type and call it on this object.
            Dim myMethodInfo As MethodInfo = myCustomClass.GetMethod("MyMethod")
            myMethodInfo.Invoke(myObject, New Object(1) {"Sample string", 3})
            ' Retrieve the values of Attributes applied to field and display to console.
            Dim myFieldInfo As FieldInfo() = myCustomClass.GetFields()
            Dim i As Integer
            For i = 0 To myFieldInfo.Length - 1
               Dim attributes As Object() = myFieldInfo(i).GetCustomAttributes(True)
               Dim index As Integer
               For index = 0 To attributes.Length - 1
                  If TypeOf attributes(index) Is MyAttribute1 Then
                     Dim myCustomAttribute As MyAttribute1 =  _
                                    CType(attributes(index), MyAttribute1)
                     Console.WriteLine("Attribute Value of (MyAttribute1): " _
                                    + myCustomAttribute.myCustomAttributeValue.ToString())
                  End If
                  If TypeOf attributes(index) Is MyAttribute2 Then
                     Dim myCustomAttribute As MyAttribute2 = _
                                    CType(attributes(index), MyAttribute2)
                     Console.WriteLine("Attribute Value of (MyAttribute2): " _
                                       + myCustomAttribute.myCustomAttributeValue.ToString())
                  End If
               Next index
            Next i
         Catch e as Exception
            Console.WriteLine("Exception Caught "+e.Message)
         End Try
      End Sub
   End Class
End Namespace 'MySample

Si applica a

SetCustomAttribute(ConstructorInfo, Byte[])

Origine:
FieldBuilder.cs
Origine:
FieldBuilder.cs
Origine:
FieldBuilder.cs

Imposta un attributo personalizzato usando un BLOB di attributi personalizzati specificato.

public:
 void SetCustomAttribute(System::Reflection::ConstructorInfo ^ con, cli::array <System::Byte> ^ binaryAttribute);
public void SetCustomAttribute (System.Reflection.ConstructorInfo con, byte[] binaryAttribute);
[System.Runtime.InteropServices.ComVisible(true)]
public void SetCustomAttribute (System.Reflection.ConstructorInfo con, byte[] binaryAttribute);
member this.SetCustomAttribute : System.Reflection.ConstructorInfo * byte[] -> unit
[<System.Runtime.InteropServices.ComVisible(true)>]
member this.SetCustomAttribute : System.Reflection.ConstructorInfo * byte[] -> unit
Public Sub SetCustomAttribute (con As ConstructorInfo, binaryAttribute As Byte())

Parametri

con
ConstructorInfo

Costruttore dell'attributo personalizzato.

binaryAttribute
Byte[]

BLOB di byte che rappresenta gli attributi.

Attributi
ComVisibleAttribute

Eccezioni

ArgumentNullException

con o binaryAttribute è null.

InvalidOperationException

Il tipo padre del campo è completo.

Esempio

Nell'esempio di codice seguente viene illustrato l'uso di SetCustomAttribute nel contesto di , usando un BLOB di FieldBuilderbyte.

using namespace System;
using namespace System::Threading;
using namespace System::Reflection;
using namespace System::Reflection::Emit;

[AttributeUsage(AttributeTargets::All,AllowMultiple=false)]
public ref class MyAttribute1: public Attribute
{
public:
   String^ myCustomAttributeValue;
   MyAttribute1( String^ myString )
   {
      myCustomAttributeValue = myString;
   }
};


[AttributeUsage(AttributeTargets::All,AllowMultiple=false)]
public ref class MyAttribute2: public Attribute
{
public:
   bool myCustomAttributeValue;
   MyAttribute2( bool myBool )
   {
      myCustomAttributeValue = myBool;
   }
};

Type^ CreateCallee( AppDomain^ currentDomain )
{
   // Create a simple name for the assembly.
   AssemblyName^ myAssemblyName = gcnew AssemblyName;
   myAssemblyName->Name = "EmittedAssembly";

   // Create the called dynamic assembly.
   AssemblyBuilder^ myAssemblyBuilder = currentDomain->DefineDynamicAssembly( myAssemblyName, AssemblyBuilderAccess::RunAndSave );
   ModuleBuilder^ myModuleBuilder = myAssemblyBuilder->DefineDynamicModule( "EmittedModule", "EmittedModule.mod" );

   // Define a public class named 'CustomClass' in the assembly.
   TypeBuilder^ myTypeBuilder = myModuleBuilder->DefineType( "CustomClass", TypeAttributes::Public );

   // Define a private String field named 'MyField' in the type.
   FieldBuilder^ myFieldBuilder = myTypeBuilder->DefineField( "MyField", String::typeid, FieldAttributes::Public );
   Type^ myAttributeType1 = MyAttribute1::typeid;

   // Create a Constructorinfo Object* for attribute 'MyAttribute1'.
   array<Type^>^type1 = {String::typeid};
   ConstructorInfo^ myConstructorInfo = myAttributeType1->GetConstructor( type1 );

   // Create the CustomAttribute instance of attribute of type 'MyAttribute1'.
   array<Object^>^obj1 = {"Test"};
   CustomAttributeBuilder^ attributeBuilder = gcnew CustomAttributeBuilder( myConstructorInfo,obj1 );

   // Set the CustomAttribute 'MyAttribute1' to the Field.
   myFieldBuilder->SetCustomAttribute( attributeBuilder );
   Type^ myAttributeType2 = MyAttribute2::typeid;

   // Create a Constructorinfo Object* for attribute 'MyAttribute2'.
   array<Type^>^type2 = {bool::typeid};
   ConstructorInfo^ myConstructorInfo2 = myAttributeType2->GetConstructor( type2 );

   // Set the CustomAttribute 'MyAttribute2' to the Field.
   array<Byte>^bytes = {01,00,01,00,00};
   myFieldBuilder->SetCustomAttribute( myConstructorInfo2, bytes );

   // Create a method.
   array<Type^>^type3 = {String::typeid,int::typeid};
   MethodBuilder^ myMethodBuilder = myTypeBuilder->DefineMethod( "MyMethod", MethodAttributes::Public, nullptr, type3 );
   ILGenerator^ myILGenerator = myMethodBuilder->GetILGenerator();
   myILGenerator->Emit( OpCodes::Ldarg_0 );
   myILGenerator->Emit( OpCodes::Ldarg_1 );
   myILGenerator->Emit( OpCodes::Stfld, myFieldBuilder );
   myILGenerator->EmitWriteLine( "Value of the Field is :" );
   myILGenerator->EmitWriteLine( myFieldBuilder );
   myILGenerator->Emit( OpCodes::Ret );
   return myTypeBuilder->CreateType();
}

int main()
{
   try
   {
      Type^ myCustomClass = CreateCallee( Thread::GetDomain() );

      // Construct an instance of a type.
      Object^ myObject = Activator::CreateInstance( myCustomClass );
      Console::WriteLine( "FieldBuilder Sample" );

      // Find a method in this type and call it on this Object*.
      MethodInfo^ myMethodInfo = myCustomClass->GetMethod( "MyMethod" );
      array<Object^>^obj1 = {"Sample string",3};
      myMethodInfo->Invoke( myObject, obj1 );

      // Retrieve the values of Attributes applied to field and display to console.
      array<FieldInfo^>^myFieldInfo = myCustomClass->GetFields();
      for ( int i = 0; i < myFieldInfo->Length; i++ )
      {
         array<Object^>^attributes = myFieldInfo[ i ]->GetCustomAttributes( true );
         for ( int index = 0; index < attributes->Length; index++ )
         {
            if ( dynamic_cast<MyAttribute1^>(attributes[ index ]) )
            {
               MyAttribute1^ myCustomAttribute = safe_cast<MyAttribute1^>(attributes[ index ]);
               Console::WriteLine( "Attribute Value of (MyAttribute1): {0}", myCustomAttribute->myCustomAttributeValue );
            }
            if ( dynamic_cast<MyAttribute2^>(attributes[ index ]) )
            {
               MyAttribute2^ myCustomAttribute = safe_cast<MyAttribute2^>(attributes[ index ]);
               Console::WriteLine( "Attribute Value of (MyAttribute2): {0}", myCustomAttribute->myCustomAttributeValue );
            }
         }
      }
   }
   catch ( Exception^ e ) 
   {
      Console::WriteLine( "Exception Caught {0}", e->Message );
   }
}


using System;
using System.Threading;
using System.Reflection;
using System.Reflection.Emit;

namespace MySample
{
   [AttributeUsage(AttributeTargets.All, AllowMultiple = false)]
   public class MyAttribute1 :Attribute
   {
      public string myCustomAttributeValue;
      public MyAttribute1(string myString)
      {
         myCustomAttributeValue = myString;
      }
   }
   [AttributeUsage(AttributeTargets.All, AllowMultiple = false)]
   public class MyAttribute2 :Attribute
   {
      public bool myCustomAttributeValue;
      public MyAttribute2(bool myBool)
      {
         myCustomAttributeValue = myBool;
      }
   }

   class FieldBuilder_Sample
   {
      private static Type CreateCallee(AppDomain currentDomain)
      {

         // Create a simple name for the assembly.
         AssemblyName myAssemblyName = new AssemblyName();
         myAssemblyName.Name = "EmittedAssembly";
         // Create the called dynamic assembly.
         AssemblyBuilder myAssemblyBuilder =
            currentDomain.DefineDynamicAssembly(myAssemblyName, AssemblyBuilderAccess.RunAndSave);
         ModuleBuilder myModuleBuilder =
                  myAssemblyBuilder.DefineDynamicModule("EmittedModule","EmittedModule.mod");
         // Define a public class named 'CustomClass' in the assembly.
         TypeBuilder myTypeBuilder = myModuleBuilder.DefineType("CustomClass",
            TypeAttributes.Public);
         // Define a private String field named 'MyField' in the type.
         FieldBuilder myFieldBuilder =
            myTypeBuilder.DefineField("MyField", typeof(String), FieldAttributes.Public);
         Type myAttributeType1 = typeof(MyAttribute1);
         // Create a Constructorinfo object for attribute 'MyAttribute1'.
         ConstructorInfo myConstructorInfo = myAttributeType1.GetConstructor(
            new Type[1]{typeof(string)});
         // Create the CustomAttribute instance of attribute of type 'MyAttribute1'.
         CustomAttributeBuilder attributeBuilder =
                     new CustomAttributeBuilder( myConstructorInfo,new object[1]{"Test"});
         // Set the CustomAttribute 'MyAttribute1' to the Field.
         myFieldBuilder.SetCustomAttribute(attributeBuilder);

          Type myAttributeType2 = typeof(MyAttribute2);
         // Create a Constructorinfo object for attribute 'MyAttribute2'.
        ConstructorInfo myConstructorInfo2 = myAttributeType2.GetConstructor(
            new Type[1]{typeof(bool)});
         // Set the CustomAttribute 'MyAttribute2' to the Field.
         myFieldBuilder.SetCustomAttribute(myConstructorInfo2,new byte[]{01,00,01,00,00});

         // Create a method.
         MethodBuilder myMethodBuilder= myTypeBuilder.DefineMethod("MyMethod",
            MethodAttributes.Public,null,new Type[2]{typeof(string),typeof(int)});

         ILGenerator myILGenerator = myMethodBuilder.GetILGenerator();
         myILGenerator.Emit(OpCodes.Ldarg_0);
         myILGenerator.Emit(OpCodes.Ldarg_1);
         myILGenerator.Emit(OpCodes.Stfld, myFieldBuilder);
         myILGenerator.EmitWriteLine("Value of the Field is :");
         myILGenerator.EmitWriteLine(myFieldBuilder);
         myILGenerator.Emit(OpCodes.Ret);

         return myTypeBuilder.CreateType();
      }
      public static void Main()
      {
         try
         {
            Type myCustomClass = CreateCallee(Thread.GetDomain());
            // Construct an instance of a type.
            Object myObject = Activator.CreateInstance(myCustomClass);
            Console.WriteLine( "FieldBuilder Sample");
            // Find a method in this type and call it on this object.
            MethodInfo myMethodInfo = myCustomClass.GetMethod("MyMethod");
            myMethodInfo.Invoke(myObject, new object[2]{"Sample string",3});
            // Retrieve the values of Attributes applied to field and display to console.
            FieldInfo[] myFieldInfo = myCustomClass.GetFields();
            for(int i =0;i<myFieldInfo.Length;i++)
            {
               object[] attributes = myFieldInfo[i].GetCustomAttributes(true);
               for(int index=0; index < attributes.Length; index++)
               {
                  if(attributes[index] is MyAttribute1)
                  {
                     MyAttribute1 myCustomAttribute = (MyAttribute1)attributes[index];
                     Console.WriteLine("Attribute Value of (MyAttribute1): "
                                       + myCustomAttribute.myCustomAttributeValue);
                  }
                  if(attributes[index] is MyAttribute2)
                  {
                     MyAttribute2 myCustomAttribute = (MyAttribute2)attributes[index];
                     Console.WriteLine("Attribute Value of (MyAttribute2): "
                                       + myCustomAttribute.myCustomAttributeValue);
                  }
               }
            }
         }
         catch (Exception e)
         {
            Console.WriteLine("Exception Caught "+e.Message);
         }
      }
   }
}

Imports System.Threading
Imports System.Reflection
Imports System.Reflection.Emit

Namespace MySample
   <AttributeUsage(AttributeTargets.All, AllowMultiple:=False)> Public Class MyAttribute1
      Inherits Attribute
      Public myCustomAttributeValue As String

      Public Sub New(ByVal myString As String)
         myCustomAttributeValue = myString
      End Sub
   End Class
   <AttributeUsage(AttributeTargets.All, AllowMultiple:=False)> Public Class MyAttribute2
      Inherits Attribute
      Public myCustomAttributeValue As Boolean

      Public Sub New(ByVal myBool As Boolean)
         myCustomAttributeValue = myBool
      End Sub
   End Class

   Class FieldBuilder_Sample

      Private Shared Function CreateCallee(ByVal currentDomain As AppDomain) As Type
         ' Create a simple name for the assembly.
         Dim myAssemblyName As New AssemblyName()
         myAssemblyName.Name = "EmittedAssembly"
         ' Create the called dynamic assembly.
         Dim myAssemblyBuilder As AssemblyBuilder = _
                     currentDomain.DefineDynamicAssembly(myAssemblyName, _
                     AssemblyBuilderAccess.RunAndSave)
         Dim myModuleBuilder As ModuleBuilder = _
               myAssemblyBuilder.DefineDynamicModule("EmittedModule", _
                                                   "EmittedModule.mod")
         ' Define a public class named 'CustomClass' in the assembly.
         Dim myTypeBuilder As TypeBuilder = myModuleBuilder.DefineType("CustomClass", _
                                                TypeAttributes.Public)
         ' Define a private String field named 'MyField' in the type.
         Dim myFieldBuilder As FieldBuilder = myTypeBuilder.DefineField("MyField", _
                                       GetType(String), FieldAttributes.Public)
         Dim myAttributeType1 As Type = GetType(MyAttribute1)
         ' Create a Constructorinfo object for attribute 'MyAttribute1'.
         Dim myConstructorInfo As ConstructorInfo = _
                     myAttributeType1.GetConstructor(New Type(0) {GetType(String)})
         ' Create the CustomAttribute instance of attribute of type 'MyAttribute1'.
         Dim attributeBuilder As _
         New CustomAttributeBuilder(myConstructorInfo, New Object(0) {"Test"})
         ' Set the CustomAttribute 'MyAttribute1' to the Field.
         myFieldBuilder.SetCustomAttribute(attributeBuilder)

         Dim myAttributeType2 As Type = GetType(MyAttribute2)
         ' Create a Constructorinfo object for attribute 'MyAttribute2'.
         Dim myConstructorInfo2 As ConstructorInfo = _
                  myAttributeType2.GetConstructor(New Type(0) {GetType(Boolean)})
         ' Set the CustomAttribute 'MyAttribute2' to the Field.
         myFieldBuilder.SetCustomAttribute(myConstructorInfo2, New Byte() {1, 0, 1, 0, 0})

         ' Create a method.
         Dim myMethodBuilder As MethodBuilder = myTypeBuilder.DefineMethod("MyMethod", _
               MethodAttributes.Public, Nothing, New Type(1) {GetType(String), GetType(Integer)})
         Dim myILGenerator As ILGenerator = myMethodBuilder.GetILGenerator()
         myILGenerator.Emit(OpCodes.Ldarg_0)
         myILGenerator.Emit(OpCodes.Ldarg_1)
         myILGenerator.Emit(OpCodes.Stfld, myFieldBuilder)
         myILGenerator.EmitWriteLine("Value of the Field is :")
         myILGenerator.EmitWriteLine(myFieldBuilder)
         myILGenerator.Emit(OpCodes.Ret)

         Return myTypeBuilder.CreateType()
      End Function 'CreateCallee

      Public Shared Sub Main()
         Try
            Dim myCustomClass As Type = CreateCallee(Thread.GetDomain())
            ' Construct an instance of a type.
            Dim myObject As Object = Activator.CreateInstance(myCustomClass)
            Console.WriteLine("FieldBuilder Sample")
            ' Find a method in this type and call it on this object.
            Dim myMethodInfo As MethodInfo = myCustomClass.GetMethod("MyMethod")
            myMethodInfo.Invoke(myObject, New Object(1) {"Sample string", 3})
            ' Retrieve the values of Attributes applied to field and display to console.
            Dim myFieldInfo As FieldInfo() = myCustomClass.GetFields()
            Dim i As Integer
            For i = 0 To myFieldInfo.Length - 1
               Dim attributes As Object() = myFieldInfo(i).GetCustomAttributes(True)
               Dim index As Integer
               For index = 0 To attributes.Length - 1
                  If TypeOf attributes(index) Is MyAttribute1 Then
                     Dim myCustomAttribute As MyAttribute1 =  _
                                    CType(attributes(index), MyAttribute1)
                     Console.WriteLine("Attribute Value of (MyAttribute1): " _
                                    + myCustomAttribute.myCustomAttributeValue.ToString())
                  End If
                  If TypeOf attributes(index) Is MyAttribute2 Then
                     Dim myCustomAttribute As MyAttribute2 = _
                                    CType(attributes(index), MyAttribute2)
                     Console.WriteLine("Attribute Value of (MyAttribute2): " _
                                       + myCustomAttribute.myCustomAttributeValue.ToString())
                  End If
               Next index
            Next i
         Catch e as Exception
            Console.WriteLine("Exception Caught "+e.Message)
         End Try
      End Sub
   End Class
End Namespace 'MySample

Commenti

Per informazioni su come formattare binaryAttribute, vedere la specifica dei metadati in Partition II della specifica Common Language Infrastructure (CLI).

Si applica a