CustomAttributeBuilder Class


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Helps build custom attributes.

Namespace:   System.Reflection.Emit
Assembly:  mscorlib (in mscorlib.dll)


[HostProtectionAttribute(SecurityAction::LinkDemand, MayLeakOnAbort = true)]
public ref class CustomAttributeBuilder : _CustomAttributeBuilder

System_CAPS_pubmethodCustomAttributeBuilder(ConstructorInfo^, array<Object^>^)

Initializes an instance of the CustomAttributeBuilder class given the constructor for the custom attribute and the arguments to the constructor.

System_CAPS_pubmethodCustomAttributeBuilder(ConstructorInfo^, array<Object^>^, array<FieldInfo^>^, array<Object^>^)

Initializes an instance of the CustomAttributeBuilder class given the constructor for the custom attribute, the arguments to the constructor, and a set of named field/value pairs.

System_CAPS_pubmethodCustomAttributeBuilder(ConstructorInfo^, array<Object^>^, array<PropertyInfo^>^, array<Object^>^)

Initializes an instance of the CustomAttributeBuilder class given the constructor for the custom attribute, the arguments to the constructor, and a set of named property or value pairs.

System_CAPS_pubmethodCustomAttributeBuilder(ConstructorInfo^, array<Object^>^, array<PropertyInfo^>^, array<Object^>^, array<FieldInfo^>^, array<Object^>^)

Initializes an instance of the CustomAttributeBuilder class given the constructor for the custom attribute, the arguments to the constructor, a set of named property or value pairs, and a set of named field or value pairs.


Determines whether the specified object is equal to the current object.(Inherited from Object.)


Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)


Serves as the default hash function. (Inherited from Object.)


Gets the Type of the current instance.(Inherited from Object.)


Creates a shallow copy of the current Object.(Inherited from Object.)


Returns a string that represents the current object.(Inherited from Object.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_CustomAttributeBuilder::GetIDsOfNames(Guid%, IntPtr, UInt32, UInt32, IntPtr)

Maps a set of names to a corresponding set of dispatch identifiers.

System_CAPS_pubinterfaceSystem_CAPS_privmethod_CustomAttributeBuilder::GetTypeInfo(UInt32, UInt32, IntPtr)

Retrieves the type information for an object, which can then be used to get the type information for an interface.


Retrieves the number of type information interfaces that an object provides (either 0 or 1).

System_CAPS_pubinterfaceSystem_CAPS_privmethod_CustomAttributeBuilder::Invoke(UInt32, Guid%, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

Provides access to properties and methods exposed by an object.

Use the CustomAttributeBuilder object returned by the constructor to describe the custom attribute. Associate the CustomAttribute with a builder instance by calling the SetCustomAttribute method on that builder instance. For example, create a CustomAttributeBuilder to describe an instance of AssemblyCultureAttribute by supplying the constructor of AssemblyCultureAttribute and its argument. Then call SetCustomAttribute on an AssemblyBuilder to establish the association.

The following code sample illustrates the use of CustomAttributeBuilder.

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

// We will apply this custom attribute to our dynamic type.
public ref class ClassCreator: public Attribute
   String^ creator;


   property String^ Creator 
      String^ get()
         return creator;

   ClassCreator( String^ name )
      this->creator = name;


// We will apply this dynamic attribute to our dynamic method.
public ref class DateLastUpdated: public Attribute
   String^ dateUpdated;


   property String^ DateUpdated 
      String^ get()
         return dateUpdated;

   DateLastUpdated( String^ theDate )
      this->dateUpdated = theDate;


Type^ BuildTypeWithCustomAttributesOnMethod()
   AppDomain^ currentDomain = Thread::GetDomain();
   AssemblyName^ myAsmName = gcnew AssemblyName;
   myAsmName->Name = "MyAssembly";
   AssemblyBuilder^ myAsmBuilder = currentDomain->DefineDynamicAssembly( myAsmName, AssemblyBuilderAccess::Run );
   ModuleBuilder^ myModBuilder = myAsmBuilder->DefineDynamicModule( "MyModule" );

   // First, we'll build a type with a custom attribute attached.
   TypeBuilder^ myTypeBuilder = myModBuilder->DefineType( "MyType", TypeAttributes::Public );
   array<Type^>^temp6 = {String::typeid};
   array<Type^>^ctorParams = temp6;
   ConstructorInfo^ classCtorInfo = ClassCreator::typeid->GetConstructor( ctorParams );
   array<Object^>^temp0 = {"Joe Programmer"};
   CustomAttributeBuilder^ myCABuilder = gcnew CustomAttributeBuilder( classCtorInfo,temp0 );
   myTypeBuilder->SetCustomAttribute( myCABuilder );

   // Now, let's build a method and add a custom attribute to it.
   array<Type^>^temp1 = gcnew array<Type^>(0);
   MethodBuilder^ myMethodBuilder = myTypeBuilder->DefineMethod( "HelloWorld", MethodAttributes::Public, nullptr, temp1 );
   array<Type^>^temp7 = {String::typeid};
   ctorParams = temp7;
   classCtorInfo = DateLastUpdated::typeid->GetConstructor( ctorParams );
   array<Object^>^temp2 = {DateTime::Now.ToString()};
   CustomAttributeBuilder^ myCABuilder2 = gcnew CustomAttributeBuilder( classCtorInfo,temp2 );
   myMethodBuilder->SetCustomAttribute( myCABuilder2 );
   ILGenerator^ myIL = myMethodBuilder->GetILGenerator();
   myIL->EmitWriteLine( "Hello, world!" );
   myIL->Emit( OpCodes::Ret );
   return myTypeBuilder->CreateType();

int main()
   Type^ myType = BuildTypeWithCustomAttributesOnMethod();
   Object^ myInstance = Activator::CreateInstance( myType );
   array<Object^>^customAttrs = myType->GetCustomAttributes( true );
   Console::WriteLine( "Custom Attributes for Type 'MyType':" );
   Object^ attrVal = nullptr;
   System::Collections::IEnumerator^ myEnum = customAttrs->GetEnumerator();
   while ( myEnum->MoveNext() )
      Object^ customAttr = safe_cast<Object^>(myEnum->Current);
      array<Object^>^temp3 = gcnew array<Object^>(0);
      attrVal = ClassCreator::typeid->InvokeMember( "Creator", BindingFlags::GetProperty, nullptr, customAttr, temp3 );
      Console::WriteLine( "-- Attribute: [{0} = \"{1}\"]", customAttr, attrVal );

   Console::WriteLine( "Custom Attributes for Method 'HelloWorld()' in 'MyType':" );
   customAttrs = myType->GetMember( "HelloWorld" )[ 0 ]->GetCustomAttributes( true );
   System::Collections::IEnumerator^ myEnum2 = customAttrs->GetEnumerator();
   while ( myEnum2->MoveNext() )
      Object^ customAttr = safe_cast<Object^>(myEnum2->Current);
      array<Object^>^temp4 = gcnew array<Object^>(0);
      attrVal = DateLastUpdated::typeid->InvokeMember( "DateUpdated", BindingFlags::GetProperty, nullptr, customAttr, temp4 );
      Console::WriteLine( "-- Attribute: [{0} = \"{1}\"]", customAttr, attrVal );

   Console::WriteLine( "---" );
   array<Object^>^temp5 = gcnew array<Object^>(0);
   Console::WriteLine( myType->InvokeMember( "HelloWorld", BindingFlags::InvokeMethod, nullptr, myInstance, temp5 ) );

.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 8.0

Any public static ( Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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