Module.IsDefined(Type, Boolean) Module.IsDefined(Type, Boolean) Module.IsDefined(Type, Boolean) Module.IsDefined(Type, Boolean) Method


Returns a value that indicates whether the specified attribute type has been applied to this module.

 virtual bool IsDefined(Type ^ attributeType, bool inherit);
public virtual bool IsDefined (Type attributeType, bool inherit);
abstract member IsDefined : Type * bool -> bool
override this.IsDefined : Type * bool -> bool
Public Overridable Function IsDefined (attributeType As Type, inherit As Boolean) As Boolean


Type Type Type Type

The type of custom attribute to test for.

Boolean Boolean Boolean Boolean

This argument is ignored for objects of this type.


true if one or more instances of attributeType have been applied to this module; otherwise, false.



attributeType is not a Type object supplied by the runtime. For example, attributeType is a TypeBuilder object.


The following example demonstrates a use of the IsDefined method.

using namespace System;
using namespace System::Reflection;

namespace ReflectionModule_Examples

   //A very simple custom attribute.

   public ref class MySimpleAttribute: public Attribute
      String^ name;

      MySimpleAttribute( String^ newName )
         name = newName;



//Define a module-level attribute.

int main()
   moduleArray = ReflectionModule_Examples::MySimpleAttribute::typeid->Assembly->GetModules( false );
   //In a simple project with only one module, the module at index
   // 0 will be the module containing these classes.
   System::Reflection::Module^ myModule = moduleArray[ 0 ];
   Type^ myType;
   myType = myModule->GetType( "ReflectionModule_Examples.MySimpleAttribute" );
   Console::WriteLine( "IsDefined(MySimpleAttribute) = {0}", myModule->IsDefined( myType, false ) );

using System;
using System.Reflection;

//Define a module-level attribute.
[module: ReflectionModule_Examples.MySimpleAttribute("module-level")]

namespace ReflectionModule_Examples
    class MyMainClass
        static void Main()
            Module[] moduleArray;
            moduleArray = typeof(MyMainClass).Assembly.GetModules(false);
            //In a simple project with only one module, the module at index
            // 0 will be the module containing these classes.
            Module myModule = moduleArray[0];

            Type myType;
            myType = myModule.GetType("ReflectionModule_Examples.MySimpleAttribute");
            Console.WriteLine("IsDefined(MySimpleAttribute) = {0}", myModule.IsDefined(myType, false));

    //A very simple custom attribute.
    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Module)]
    public class MySimpleAttribute : Attribute
        private string name;

        public MySimpleAttribute(string newName)
            name = newName;
Imports System.Reflection

'Define a module-level attribute.
<Module: ReflectionModule_Examples.MySimpleAttribute("module-level")> 

'Define a module-level attribute.
Namespace ReflectionModule_Examples
    Class MyMainClass
        Shared Sub Main()
            Dim moduleArray() As [Module]

            moduleArray = GetType(MyMainClass).Assembly.GetModules(False)

            'In a simple project with only one module, the module at index
            ' 0 will be the module containing these classes.
            Dim myModule As [Module] = moduleArray(0)

            Dim myType As Type
            myType = myModule.GetType("ReflectionModule_Examples.MySimpleAttribute")
            Console.WriteLine("IsDefined(MySimpleAttribute) = {0}", myModule.IsDefined(myType, False))
        End Sub 'Main
    End Class 'MyMainClass

    'A very simple custom attribute.
    <AttributeUsage(AttributeTargets.Class Or AttributeTargets.Module)> _
    Public Class MySimpleAttribute
        Inherits Attribute
        Private name As String

        Public Sub New(ByVal newName As String)
            name = newName
        End Sub 'New
    End Class 'MySimpleAttribute
End Namespace 'ReflectionModule_Examples

Applies to