EnumBuilder.GetCustomAttributes Method (System.Reflection.Emit) (original) (raw)

Source:

EnumBuilder.cs

Returns the custom attributes identified by the given type.

public:
 override cli::array <System::Object ^> ^ GetCustomAttributes(Type ^ attributeType, bool inherit);

public override object[] GetCustomAttributes(Type attributeType, bool inherit);

override this.GetCustomAttributes : Type * bool -> obj[]

Public Overrides Function GetCustomAttributes (attributeType As Type, inherit As Boolean) As Object()

Parameters

attributeType

Type

The Type object to which the custom attributes are applied.

inherit

Boolean

Specifies whether to search this member's inheritance chain to find the attributes.

Returns

Returns an array of objects representing the attributes of this constructor that are of TypeattributeType.

Exceptions

This method is not currently supported in types that are not complete.

Remarks

As a workaround, to retrieve the custom attributes of a finished type, retrieve the type using Type.GetType and call MemberInfo.GetCustomAttributes on the returned Type.

The following code sample illustrates the use of GetCustomAttribute in the context of EnumBuilder.

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

   public MyAttribute(String myString1, int myInteger1)
   {
      this.myString = myString1;
      this.myInteger = myInteger1;
   }
}

class MyApplication
{
   static AssemblyBuilder myAssemblyBuilder;
   static EnumBuilder myEnumBuilder;

   public static void Main()
   {
      try
      {
         CreateCallee(Thread.GetDomain());
         if(myEnumBuilder.IsDefined(typeof(MyAttribute),false))
         {
            object[] myAttributesArray = myEnumBuilder.GetCustomAttributes(typeof(MyAttribute),false);
            Console.WriteLine("Custom attribute contains: ");
            // Read the attributes and display them on the console.
            for(int index=0; index < myAttributesArray.Length; index++)
            {
               if(myAttributesArray[index] is MyAttribute)
               {
                  Console.WriteLine("The value of myString  is: "
                                    + ((MyAttribute)myAttributesArray[index]).myString);
                  Console.WriteLine("The value of myInteger is: "
                                    + ((MyAttribute)myAttributesArray[index]).myInteger);
               }
            }
         }
         else
         {
            Console.WriteLine("Custom Attributes are not set for the EnumBuilder");
         }
      }
      catch(Exception e)
      {
         Console.WriteLine("The following exception is raised:" +e.Message);
      }
  }

   private static void CreateCallee(AppDomain domain)
   {
      // Create a name for the assembly.
      AssemblyName myAssemblyName = new AssemblyName();
      myAssemblyName.Name = "EmittedAssembly";

      // Create the dynamic assembly.
      myAssemblyBuilder = domain.DefineDynamicAssembly(myAssemblyName, AssemblyBuilderAccess.Run);

      Type myType = typeof(MyAttribute);
      ConstructorInfo myInfo = myType.GetConstructor(new Type[2]{typeof(String), typeof(int)});
      CustomAttributeBuilder myCustomAttributeBuilder =
                                    new CustomAttributeBuilder(myInfo, new object[2]{"Hello", 2});

      // Create a dynamic module.
      ModuleBuilder myModuleBuilder = myAssemblyBuilder.DefineDynamicModule("EmittedModule");

      // Create a dynamic Enum.
      myEnumBuilder = myModuleBuilder.DefineEnum("MyNamespace.MyEnum", TypeAttributes.Public, typeof(Int32));

      FieldBuilder myFieldBuilder1 = myEnumBuilder.DefineLiteral("FieldOne", 1);
      FieldBuilder myFieldBuilder2 = myEnumBuilder.DefineLiteral("FieldTwo", 2);

      myEnumBuilder.CreateType();
      myEnumBuilder.SetCustomAttribute(myCustomAttributeBuilder);
   }
}

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

   Public Sub New(myString1 As String, myInteger1 As Integer)
      Me.myString = myString1
      Me.myInteger = myInteger1
   End Sub
End Class

Class MyApplication
   Private Shared myAssemblyBuilder As AssemblyBuilder
   Private Shared myEnumBuilder As EnumBuilder

   Public Shared Sub Main()
      Try
         CreateCallee(Thread.GetDomain())
         If myEnumBuilder.IsDefined(GetType(MyAttribute), False) Then
            Dim myAttributesArray As Object() = myEnumBuilder.GetCustomAttributes _
                                                      (GetType(MyAttribute), False)
            Console.WriteLine("Custom attribute contains: ")
            ' Read the attributes and display them on the console.
            Dim index As Integer
            For index = 0 To myAttributesArray.Length - 1
               If TypeOf myAttributesArray(index) Is MyAttribute Then
                  Console.WriteLine("The value of myString  is: " + CType(myAttributesArray(index), _
                                                                           MyAttribute).myString)
                  Console.WriteLine("The value of myInteger is: " + CType(myAttributesArray(index), _
                                                               MyAttribute).myInteger.ToString())
               End If
            Next index
         Else
            Console.WriteLine("Custom Attributes are not set for the EnumBuilder")
         End If
      Catch e As Exception
         Console.WriteLine("The following exception is raised:" + e.Message)
      End Try
   End Sub

   Private Shared Sub CreateCallee(domain As AppDomain)
      ' Create a name for the assembly.
      Dim myAssemblyName As New AssemblyName()
      myAssemblyName.Name = "EmittedAssembly"

      ' Create the dynamic assembly.
      myAssemblyBuilder = domain.DefineDynamicAssembly(myAssemblyName, AssemblyBuilderAccess.Run)

      Dim myType As Type = GetType(MyAttribute)
      Dim myInfo As ConstructorInfo = myType.GetConstructor(New Type(1) {GetType(String), _
                                                                           GetType(Integer)})
      Dim myCustomAttributeBuilder As New CustomAttributeBuilder(myInfo, New Object(1) {"Hello", 2})

      ' Create a dynamic module.
      Dim myModuleBuilder As ModuleBuilder = myAssemblyBuilder.DefineDynamicModule("EmittedModule")

      ' Create a dynamic Enum.
      myEnumBuilder = myModuleBuilder.DefineEnum("MyNamespace.MyEnum", TypeAttributes.Public, _
                                                                                 GetType(Int32))

      Dim myFieldBuilder1 As FieldBuilder = myEnumBuilder.DefineLiteral("FieldOne", 1)
      Dim myFieldBuilder2 As FieldBuilder = myEnumBuilder.DefineLiteral("FieldTwo", 2)

      myEnumBuilder.CreateType()
      myEnumBuilder.SetCustomAttribute(myCustomAttributeBuilder)
   End Sub
End Class

Applies to