ConstructorBuilder.SetCustomAttribute Method

Definition

Sets a custom attribute.

Overloads

SetCustomAttribute(CustomAttributeBuilder)

Set a custom attribute using a custom attribute builder.

SetCustomAttribute(ConstructorInfo, Byte[])

Set a custom attribute using a specified custom attribute blob.

SetCustomAttribute(CustomAttributeBuilder)

Set a custom attribute using a custom attribute builder.

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)

Parameters

customBuilder
CustomAttributeBuilder

An instance of a helper class to define the custom attribute.

Exceptions

customBuilder is null.

Examples

The following code sample illustrates the use of SetCustomAttribute of the context of a ConstructorBuilder, passing a CustomAttributeBuilder.

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

[AttributeUsage(AttributeTargets::All,AllowMultiple=false)]
public ref class MyAttribute: public Attribute
{
public:
   String^ myString;
   int myInteger;
   MyAttribute( String^ myString, int myInteger )
   {
      this->myString = myString;
      this->myInteger = myInteger;
   }

};

static Type^ MyCreateCallee( AppDomain^ domain )
{
   AssemblyName^ myAssemblyName = gcnew AssemblyName;
   myAssemblyName->Name = "EmittedAssembly";

   // Define a dynamic assembly in the current application domain->
   AssemblyBuilder^ myAssembly = domain->DefineDynamicAssembly( myAssemblyName, AssemblyBuilderAccess::Run );

   // Define a dynamic module in this assembly->
   ModuleBuilder^ myModuleBuilder = myAssembly->DefineDynamicModule( "EmittedModule" );

   // Construct a 'TypeBuilder' given the name and attributes.
   TypeBuilder^ myTypeBuilder = myModuleBuilder->DefineType( "HelloWorld", TypeAttributes::Public );

   // Define a constructor of the dynamic class.
   array<Type^>^type1 = {String::typeid};
   ConstructorBuilder^ myConstructor = myTypeBuilder->DefineConstructor( MethodAttributes::Public, CallingConventions::Standard, type1 );
   ILGenerator^ myILGenerator = myConstructor->GetILGenerator();
   myILGenerator->Emit( OpCodes::Ldstr, "Constructor is invoked" );
   myILGenerator->Emit( OpCodes::Ldarg_1 );
   array<Type^>^type2 = {String::typeid};
   MethodInfo^ myMethodInfo = Console::typeid->GetMethod( "WriteLine", type2 );
   myILGenerator->Emit( OpCodes::Call, myMethodInfo );
   myILGenerator->Emit( OpCodes::Ret );
   Type^ myType = MyAttribute::typeid;
   array<Type^>^type3 = {String::typeid,int::typeid};
   ConstructorInfo^ myConstructorInfo = myType->GetConstructor( type3 );
   array<Object^>^obj1 = {"Hello",2};
   CustomAttributeBuilder^ attributeBuilder = gcnew CustomAttributeBuilder( myConstructorInfo,obj1 );
   try
   {
      myConstructor->SetCustomAttribute( attributeBuilder );
   }
   catch ( ArgumentNullException^ ex ) 
   {
      Console::WriteLine( "The following exception has occurred : {0}", ex->Message );
   }
   catch ( Exception^ ex ) 
   {
      Console::WriteLine( "The following exception has occurred : {0}", ex->Message );
   }

   return myTypeBuilder->CreateType();
}

int main()
{
   Type^ myHelloworld = MyCreateCallee( Thread::GetDomain() );
   array<Type^>^type1 = {String::typeid};
   ConstructorInfo^ myConstructor = myHelloworld->GetConstructor( type1 );
   array<Object^>^myAttributes1 = myConstructor->GetCustomAttributes( true );
   Console::WriteLine( "MyAttribute custom attribute contains  " );
   for ( int index = 0; index < myAttributes1->Length; index++ )
   {
      if ( dynamic_cast<MyAttribute^>(myAttributes1[ index ]) )
      {
         Console::WriteLine( "The value of myString is : {0}", (safe_cast<MyAttribute^>(myAttributes1[ index ]))->myString );
         Console::WriteLine( "The value of myInteger is : {0}", (safe_cast<MyAttribute^>(myAttributes1[ index ]))->myInteger );
      }
   }
}
using System;
using System.Threading;
using System.Reflection;
using System.Reflection.Emit;

[AttributeUsage(AttributeTargets.All, AllowMultiple = false)]
public class MyAttribute : Attribute
{
   public String myString;
   public int myInteger;
   public MyAttribute(String myString, int myInteger)
   {
      this.myString = myString;
      this.myInteger = myInteger;
   }
}

public class MyConstructorBuilder
{
   public static void Main()
   {
      Type myHelloworld = MyCreateCallee(Thread.GetDomain());
      ConstructorInfo myConstructor = myHelloworld.GetConstructor(new Type[]{typeof(String)});
      object[] myAttributes1 = myConstructor.GetCustomAttributes(true);
      Console.WriteLine("MyAttribute custom attribute contains  ");
      for(int index=0; index < myAttributes1.Length; index++)
      {
         if(myAttributes1[index] is MyAttribute)
         {
            Console.WriteLine("The value of myString is : "
                                       + ((MyAttribute)myAttributes1[index]).myString);
            Console.WriteLine("The value of myInteger is : "
                                       + ((MyAttribute)myAttributes1[index]).myInteger);
         }
      }
   }

   private static Type MyCreateCallee(AppDomain domain)
   {
      AssemblyName myAssemblyName = new AssemblyName();
      myAssemblyName.Name = "EmittedAssembly";
      // Define a dynamic assembly in the current application domain.
      AssemblyBuilder myAssembly =
                  domain.DefineDynamicAssembly(myAssemblyName,AssemblyBuilderAccess.Run);
      // Define a dynamic module in this assembly.
      ModuleBuilder myModuleBuilder = myAssembly.DefineDynamicModule("EmittedModule");
       // Construct a 'TypeBuilder' given the name and attributes.
      TypeBuilder myTypeBuilder = myModuleBuilder.DefineType("HelloWorld",
         TypeAttributes.Public);
      // Define a constructor of the dynamic class.
      ConstructorBuilder myConstructor = myTypeBuilder.DefineConstructor(
               MethodAttributes.Public, CallingConventions.Standard, new Type[]{typeof(String)});
      ILGenerator myILGenerator = myConstructor.GetILGenerator();
      myILGenerator.Emit(OpCodes.Ldstr, "Constructor is invoked");
      myILGenerator.Emit(OpCodes.Ldarg_1);
      MethodInfo myMethodInfo =
                     typeof(Console).GetMethod("WriteLine",new Type[]{typeof(string)});
      myILGenerator.Emit(OpCodes.Call, myMethodInfo);
      myILGenerator.Emit(OpCodes.Ret);
      Type myType = typeof(MyAttribute);
      ConstructorInfo myConstructorInfo = myType.GetConstructor(new Type[2]{typeof(String), typeof(int)});
      CustomAttributeBuilder attributeBuilder =
         new CustomAttributeBuilder(myConstructorInfo, new object[2]{"Hello", 2});
      try
      {
         myConstructor.SetCustomAttribute(attributeBuilder);
      }
      catch(ArgumentNullException ex)
      {
         Console.WriteLine("The following exception has occurred : "+ex.Message);
      }
      catch(Exception ex)
      {
         Console.WriteLine("The following exception has occurred : "+ex.Message);
      }
      return myTypeBuilder.CreateType();
   }
}
Imports System.Threading
Imports System.Reflection
Imports System.Reflection.Emit


<AttributeUsage(AttributeTargets.All, AllowMultiple := False)>  _
Public Class MyAttribute
   Inherits Attribute
   Public myString As String
   Public myInteger As Integer
   
   Public Sub New(myString As String, myInteger As Integer)
      Me.myString = myString
      Me.myInteger = myInteger
   End Sub
End Class

Public Class MyConstructorBuilder
   
   Public Shared Sub Main()
      Dim myHelloworld As Type = MyCreateCallee(Thread.GetDomain())
      Dim myConstructor As ConstructorInfo = myHelloworld.GetConstructor(New Type() _ 
                                                                       {GetType(String)})
      Dim myAttributes1 As Object() = myConstructor.GetCustomAttributes(True)
      Console.WriteLine("MyAttribute custom attribute contains  ")
      Dim index As Integer
      For index = 0 To myAttributes1.Length - 1
         If TypeOf myAttributes1(index) Is MyAttribute Then
            Console.WriteLine("The value of myString is : " + CType(myAttributes1(index), _ 
                                                                       MyAttribute).myString)
            Console.WriteLine("The value of myInteger is : " + CType(myAttributes1(index), _ 
                                                            MyAttribute).myInteger.ToString())
         End If
      Next index
   End Sub
   
   Private Shared Function MyCreateCallee(domain As AppDomain) As Type
      Dim myAssemblyName As New AssemblyName()
      myAssemblyName.Name = "EmittedAssembly"
      ' Define a dynamic assembly in the current application domain.
      Dim myAssembly As AssemblyBuilder = domain.DefineDynamicAssembly _ 
                                          (myAssemblyName, AssemblyBuilderAccess.Run)
      ' Define a dynamic module in this assembly.
      Dim myModuleBuilder As ModuleBuilder = myAssembly.DefineDynamicModule("EmittedModule")
      ' Construct a 'TypeBuilder' given the name and attributes.
      Dim myTypeBuilder As TypeBuilder = myModuleBuilder.DefineType _ 
                                                       ("HelloWorld", TypeAttributes.Public)
      ' Define a constructor of the dynamic class.
      Dim myConstructor As ConstructorBuilder = myTypeBuilder.DefineConstructor _ 
             (MethodAttributes.Public, CallingConventions.Standard, New Type() {GetType(String)})
      Dim myILGenerator As ILGenerator = myConstructor.GetILGenerator()
      myILGenerator.Emit(OpCodes.Ldstr, "Constructor is invoked")
      myILGenerator.Emit(OpCodes.Ldarg_1)
      Dim myMethodInfo As MethodInfo = GetType(Console).GetMethod("WriteLine", New Type() _ 
                                                                           {GetType(String)})
      myILGenerator.Emit(OpCodes.Call, myMethodInfo)
      myILGenerator.Emit(OpCodes.Ret)
      Dim myType As Type = GetType(MyAttribute)
      Dim myConstructorInfo As ConstructorInfo = myType.GetConstructor(New Type(1) _ 
                                                           {GetType(String), GetType(Integer)})
      Dim attributeBuilder As New CustomAttributeBuilder _ 
                                  (myConstructorInfo, New Object(1) {"Hello", 2})
      Try
         myConstructor.SetCustomAttribute(attributeBuilder)
      Catch ex As ArgumentNullException
         Console.WriteLine("The following exception has occurred : " + ex.Message)
      Catch ex As Exception
         Console.WriteLine("The following exception has occurred : " + ex.Message)
      End Try
      Return myTypeBuilder.CreateType()
   End Function 'MyCreateCallee
End Class

SetCustomAttribute(ConstructorInfo, Byte[])

Set a custom attribute using a specified custom attribute blob.

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())

Parameters

con
ConstructorInfo

The constructor for the custom attribute.

binaryAttribute
Byte[]

A byte blob representing the attributes.

Attributes

Exceptions

con or binaryAttribute is null.

Examples

The following code sample illustrates the use of SetCustomAttribute of the context of a ConstructorBuilder, passing a byte blob.

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

[AttributeUsage(AttributeTargets::All,AllowMultiple=false)]
public ref class MyAttribute: public Attribute
{
public:
   bool myBoolean;
   MyAttribute( bool myBoolean )
   {
      this->myBoolean = myBoolean;
   }
};

static Type^ MyCreateCallee( AppDomain^ domain )
{
   AssemblyName^ myAssemblyName = gcnew AssemblyName;
   myAssemblyName->Name = "EmittedAssembly";
   
   // Define a dynamic assembly in the current application domain.
   AssemblyBuilder^ myAssembly = domain->DefineDynamicAssembly( myAssemblyName, AssemblyBuilderAccess::Run );
   
   // Define a dynamic module in this assembly.
   ModuleBuilder^ myModuleBuilder = myAssembly->DefineDynamicModule( "EmittedModule" );
   
   // Construct a 'TypeBuilder' given the name and attributes.
   TypeBuilder^ myTypeBuilder = myModuleBuilder->DefineType( "HelloWorld", TypeAttributes::Public );
   
   // Define a constructor of the dynamic class.
   array<Type^>^type1 = {String::typeid};
   ConstructorBuilder^ myConstructor = myTypeBuilder->DefineConstructor( MethodAttributes::Public, CallingConventions::Standard, type1 );
   ILGenerator^ myILGenerator = myConstructor->GetILGenerator();
   myILGenerator->Emit( OpCodes::Ldstr, "Constructor is invoked" );
   myILGenerator->Emit( OpCodes::Ldarg_1 );
   array<Type^>^type2 = {String::typeid};
   MethodInfo^ myMethodInfo = Console::typeid->GetMethod( "WriteLine", type2 );
   myILGenerator->Emit( OpCodes::Call, myMethodInfo );
   myILGenerator->Emit( OpCodes::Ret );
   Type^ myType = MyAttribute::typeid;
   array<Type^>^type3 = {bool::typeid};
   ConstructorInfo^ myConstructorInfo = myType->GetConstructor( type3 );
   try
   {
      array<Byte>^bytes = {01,00,01};
      myConstructor->SetCustomAttribute( myConstructorInfo, bytes );
   }
   catch ( ArgumentNullException^ ex ) 
   {
      Console::WriteLine( "The following exception has occurred : {0}", ex->Message );
   }
   catch ( Exception^ ex ) 
   {
      Console::WriteLine( "The following exception has occurred : {0}", ex->Message );
   }

   return myTypeBuilder->CreateType();
}

int main()
{
   Type^ myHelloworld = MyCreateCallee( Thread::GetDomain() );
   array<Type^>^type1 = {String::typeid};
   ConstructorInfo^ myConstructor = myHelloworld->GetConstructor( type1 );
   array<Object^>^myAttributes1 = myConstructor->GetCustomAttributes( true );
   Console::WriteLine( "MyAttribute custom attribute contains  " );
   for ( int index = 0; index < myAttributes1->Length; index++ )
   {
      if ( dynamic_cast<MyAttribute^>(myAttributes1[ index ]) )
      {
         Console::WriteLine( "myBoolean : {0}", safe_cast<MyAttribute^>(myAttributes1[ index ])->myBoolean );
      }
   }
}
using System;
using System.Threading;
using System.Reflection;
using System.Reflection.Emit;

[AttributeUsage(AttributeTargets.All, AllowMultiple = false)]
public class MyAttribute : Attribute
{
   public bool myBoolean;

   public MyAttribute(bool myBoolean)
   {
      this.myBoolean = myBoolean;
   }
}

public class MyConstructorBuilder
{
   public static void Main()
   {
      Type myHelloworld = MyCreateCallee(Thread.GetDomain());
      ConstructorInfo myConstructor = myHelloworld.GetConstructor(new Type[]{typeof(String)});
      object[] myAttributes1 = myConstructor.GetCustomAttributes(true);
      Console.WriteLine("MyAttribute custom attribute contains  ");
      for(int index=0; index < myAttributes1.Length; index++)
      {
         if(myAttributes1[index] is MyAttribute)
         {
            Console.WriteLine("myBoolean : " + ((MyAttribute)myAttributes1[index]).myBoolean);
         }
      }
   }

   private static Type MyCreateCallee(AppDomain domain)
   {
      AssemblyName myAssemblyName = new AssemblyName();
      myAssemblyName.Name = "EmittedAssembly";
      // Define a dynamic assembly in the current application domain.
      AssemblyBuilder myAssembly =
                  domain.DefineDynamicAssembly(myAssemblyName,AssemblyBuilderAccess.Run);
      // Define a dynamic module in this assembly.
      ModuleBuilder myModuleBuilder = myAssembly.DefineDynamicModule("EmittedModule");
      // Construct a 'TypeBuilder' given the name and attributes.
      TypeBuilder myTypeBuilder = myModuleBuilder.DefineType("HelloWorld",
         TypeAttributes.Public);
      // Define a constructor of the dynamic class.
      ConstructorBuilder myConstructor = myTypeBuilder.DefineConstructor(
               MethodAttributes.Public, CallingConventions.Standard, new Type[]{typeof(String)});
      ILGenerator myILGenerator = myConstructor.GetILGenerator();
      myILGenerator.Emit(OpCodes.Ldstr, "Constructor is invoked");
      myILGenerator.Emit(OpCodes.Ldarg_1);
      MethodInfo myMethodInfo =
                     typeof(Console).GetMethod("WriteLine",new Type[]{typeof(string)});
      myILGenerator.Emit(OpCodes.Call, myMethodInfo);
      myILGenerator.Emit(OpCodes.Ret);
      Type myType = typeof(MyAttribute);
      ConstructorInfo myConstructorInfo = myType.GetConstructor(new Type[]{typeof(bool)});
      try
      {
         myConstructor.SetCustomAttribute(myConstructorInfo, new byte[]{01,00,01});
      }
      catch(ArgumentNullException ex)
      {
         Console.WriteLine("The following exception has occurred : "+ex.Message);
      }
      catch(Exception ex)
      {
         Console.WriteLine("The following exception has occurred : "+ex.Message);
      }
      return myTypeBuilder.CreateType();
   }
}
Imports System.Threading
Imports System.Reflection
Imports System.Reflection.Emit

<AttributeUsage(AttributeTargets.All, AllowMultiple := False)>  _
Public Class MyAttribute
   Inherits Attribute
   Public myBoolean As Boolean

   Public Sub New(myBoolean As Boolean)
      Me.myBoolean = myBoolean
   End Sub
End Class

Public Class MyConstructorBuilder

   Public Shared Sub Main()
      Dim myHelloworld As Type = MyCreateCallee(Thread.GetDomain())
      Dim myConstructor As ConstructorInfo = myHelloworld.GetConstructor(New Type() _
                                                                        {GetType(String)})
      Dim myAttributes1 As Object() = myConstructor.GetCustomAttributes(True)
      Console.WriteLine("MyAttribute custom attribute contains  ")
      Dim index As Integer
      For index = 0 To myAttributes1.Length - 1
         If TypeOf myAttributes1(index) Is MyAttribute Then
            Console.WriteLine("myBoolean : " + _
                               CType(myAttributes1(index), MyAttribute).myBoolean.ToString())
         End If
      Next index
   End Sub

   Private Shared Function MyCreateCallee(domain As AppDomain) As Type
      Dim myAssemblyName As New AssemblyName()
      myAssemblyName.Name = "EmittedAssembly"
      ' Define a dynamic assembly in the current application domain.
      Dim myAssembly As AssemblyBuilder = domain.DefineDynamicAssembly _
                                       (myAssemblyName, AssemblyBuilderAccess.Run)
      ' Define a dynamic module in this assembly.
      Dim myModuleBuilder As ModuleBuilder = myAssembly.DefineDynamicModule("EmittedModule")
      ' Construct a 'TypeBuilder' given the name and attributes.
      Dim myTypeBuilder As TypeBuilder = myModuleBuilder.DefineType _
                                                       ("HelloWorld", TypeAttributes.Public)
      ' Define a constructor of the dynamic class.
      Dim myConstructor As ConstructorBuilder = myTypeBuilder.DefineConstructor _
                (MethodAttributes.Public, CallingConventions.Standard, New Type() {GetType(String)})
      Dim myILGenerator As ILGenerator = myConstructor.GetILGenerator()
      myILGenerator.Emit(OpCodes.Ldstr, "Constructor is invoked")
      myILGenerator.Emit(OpCodes.Ldarg_1)
      Dim myMethodInfo As MethodInfo = GetType(Console).GetMethod("WriteLine", New Type() _
                                                                          {GetType(String)})
      myILGenerator.Emit(OpCodes.Call, myMethodInfo)
      myILGenerator.Emit(OpCodes.Ret)
      Dim myType As Type = GetType(MyAttribute)
      Dim myConstructorInfo As ConstructorInfo = myType.GetConstructor(New Type() {GetType(Boolean)})
      Try
         myConstructor.SetCustomAttribute(myConstructorInfo, New Byte() {1, 0, 1})
      Catch ex As ArgumentNullException
         Console.WriteLine("The following exception has occurred : " + ex.Message)
      Catch ex As Exception
         Console.WriteLine("The following exception has occurred : " + ex.Message)
      End Try
      Return myTypeBuilder.CreateType()
   End Function 'MyCreateCallee
End Class

Remarks

See the metadata specification in the ECMA Partition II documentation for details on how to format binaryAttribute. The documentation is available online; see ECMA C# and Common Language Infrastructure Standards on MSDN and Standard ECMA-335 - Common Language Infrastructure (CLI) on the Ecma International Web site.

Applies to