CustomAttributeBuilder Class

Helps build custom attributes.

System.Object
  System.Reflection.Emit.CustomAttributeBuilder

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

'Declaration
<ComVisibleAttribute(True)> _
<ClassInterfaceAttribute(ClassInterfaceType.None)> _
<HostProtectionAttribute(SecurityAction.LinkDemand, MayLeakOnAbort := True)> _
Public Class CustomAttributeBuilder _
	Implements _CustomAttributeBuilder

The CustomAttributeBuilder type exposes the following members.

  NameDescription
Public methodCustomAttributeBuilder(ConstructorInfo, Object())Initializes an instance of the CustomAttributeBuilder class given the constructor for the custom attribute and the arguments to the constructor.
Public methodCustomAttributeBuilder(ConstructorInfo, Object(), FieldInfo(), 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.
Public methodCustomAttributeBuilder(ConstructorInfo, Object(), PropertyInfo(), 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.
Public methodCustomAttributeBuilder(ConstructorInfo, Object(), PropertyInfo(), Object(), FieldInfo(), 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.
Top

  NameDescription
Public methodEquals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeServes as the default hash function. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
Top

  NameDescription
Explicit interface implemetationPrivate method_CustomAttributeBuilder.GetIDsOfNamesMaps a set of names to a corresponding set of dispatch identifiers.
Explicit interface implemetationPrivate method_CustomAttributeBuilder.GetTypeInfoRetrieves the type information for an object, which can then be used to get the type information for an interface.
Explicit interface implemetationPrivate method_CustomAttributeBuilder.GetTypeInfoCountRetrieves the number of type information interfaces that an object provides (either 0 or 1).
Explicit interface implemetationPrivate method_CustomAttributeBuilder.InvokeProvides access to properties and methods exposed by an object.
Top

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.

NoteNote

The HostProtectionAttribute attribute applied to this type or member has the following Resources property value: MayLeakOnAbort. The HostProtectionAttribute does not affect desktop applications (which are typically started by double-clicking an icon, typing a command, or entering a URL in a browser). For more information, see the HostProtectionAttribute class or SQL Server Programming and Host Protection Attributes.

The following code sample illustrates the use of CustomAttributeBuilder.


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

 _


' We will apply this custom attribute to our dynamic type. 
Public Class ClassCreator

   Inherits Attribute

   Private creator As String 

   Public ReadOnly Property GetCreator() As String 
      Get 
         Return creator
      End Get 
   End Property 


   Public Sub New(name As String)
      Me.creator = name
   End Sub 'New 

End Class 'ClassCreator
 _ 

' We will apply this dynamic attribute to our dynamic method. 
Public Class DateLastUpdated

   Inherits Attribute

   Private dateUpdated As String 

   Public ReadOnly Property GetDateUpdated() As String 
      Get 
         Return dateUpdated
      End Get 
   End Property 


   Public Sub New(theDate As String)
      Me.dateUpdated = theDate
   End Sub 'New 

End Class 'DateLastUpdated
 _ 

Class MethodBuilderCustomAttributesDemo

   Public Shared Function BuildTypeWithCustomAttributesOnMethod() As Type

      Dim currentDomain As AppDomain = Thread.GetDomain()

      Dim myAsmName As New AssemblyName()
      myAsmName.Name = "MyAssembly" 

      Dim myAsmBuilder As AssemblyBuilder = currentDomain.DefineDynamicAssembly(myAsmName, _
							AssemblyBuilderAccess.Run)

      Dim myModBuilder As ModuleBuilder = myAsmBuilder.DefineDynamicModule("MyModule")

      ' First, we'll build a type with a custom attribute attached. 
      Dim myTypeBuilder As TypeBuilder = myModBuilder.DefineType("MyType", _
							TypeAttributes.Public)

      Dim ctorParams() As Type = {GetType(String)}
      Dim classCtorInfo As ConstructorInfo = GetType(ClassCreator).GetConstructor(ctorParams)

      Dim myCABuilder As New CustomAttributeBuilder(classCtorInfo, _
						New Object() {"Joe Programmer"})

      myTypeBuilder.SetCustomAttribute(myCABuilder)

      ' Now, let's build a method and add a custom attribute to it. 
      Dim myMethodBuilder As MethodBuilder = myTypeBuilder.DefineMethod("HelloWorld", _
					MethodAttributes.Public, Nothing, New Type() {})

      ctorParams = New Type() {GetType(String)}
      classCtorInfo = GetType(DateLastUpdated).GetConstructor(ctorParams)

      Dim myCABuilder2 As New CustomAttributeBuilder(classCtorInfo, _
						New Object() {DateTime.Now.ToString()})

      myMethodBuilder.SetCustomAttribute(myCABuilder2)

      Dim myIL As ILGenerator = myMethodBuilder.GetILGenerator()

      myIL.EmitWriteLine("Hello, world!")
      myIL.Emit(OpCodes.Ret)

      Return myTypeBuilder.CreateType()

   End Function 'BuildTypeWithCustomAttributesOnMethod


   Public Shared Sub Main()

      Dim myType As Type = BuildTypeWithCustomAttributesOnMethod()

      Dim myInstance As Object = Activator.CreateInstance(myType)

      Dim customAttrs As Object() = myType.GetCustomAttributes(True)

      Console.WriteLine("Custom Attributes for Type 'MyType':")

      Dim attrVal As Object = Nothing 

      Dim customAttr As Object 
      For Each customAttr In  customAttrs
         attrVal = GetType(ClassCreator).InvokeMember("GetCreator", _
						BindingFlags.GetProperty, _
						Nothing, customAttr, New Object() {})
         Console.WriteLine("-- Attribute: [{0} = ""{1}""]", customAttr, attrVal)
      Next customAttr

      Console.WriteLine("Custom Attributes for Method 'HelloWorld()' in 'MyType':")

      customAttrs = myType.GetMember("HelloWorld")(0).GetCustomAttributes(True)

      For Each customAttr In  customAttrs
         attrVal = GetType(DateLastUpdated).InvokeMember("GetDateUpdated", _
						BindingFlags.GetProperty, _
						Nothing, customAttr, New Object() {})
         Console.WriteLine("-- Attribute: [{0} = ""{1}""]", customAttr, attrVal)
      Next customAttr

      Console.WriteLine("---")

      Console.WriteLine(myType.InvokeMember("HelloWorld", BindingFlags.InvokeMethod, _
						Nothing, myInstance, New Object() {}))
   End Sub 'Main

End Class 'MethodBuilderCustomAttributesDemo

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
Was this page helpful?
(1500 characters remaining)
Thank you for your feedback
Show:
© 2014 Microsoft