MemberInfo::IsDefined Method

When overridden in a derived class, indicates whether one or more attributes of the specified type or of its derived types is applied to this member.

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

virtual bool IsDefined(
	Type^ attributeType, 
	bool inherit
) abstract


Type: System::Type

The type of custom attribute to search for. The search includes derived types.

Type: System::Boolean

true to search this member's inheritance chain to find the attributes; otherwise, false. This parameter is ignored for properties and events; see Remarks.

Return Value

Type: System::Boolean
true if one or more instances of attributeType or any of its derived types is applied to this member; otherwise, false.


ICustomAttributeProvider::IsDefined(Type, Boolean)
_MemberInfo::IsDefined(Type, Boolean)

This method ignores the inherit parameter for properties and events. To search the inheritance chain for attributes on properties and events, use the appropriate overloads of the Attribute::IsDefined method.


In the .NET Framework version 2.0, this method returns true if a type, method, or constructor has security attributes stored in the new metadata format. Assemblies compiled with version 2.0 use this format. Dynamic assemblies and assemblies compiled with earlier versions of the .NET Framework use the old XML format. See Emitting Declarative Security Attributes.

The following example determines whether the specified attribute is applied to the specified member.

using namespace System;
using namespace System::Reflection;

// Define a custom attribute with one named parameter.

public ref class MyAttribute: public Attribute
   String^ myName;

   MyAttribute( String^ name )
      myName = name;

   property String^ Name 
      String^ get()
         return myName;

// Define a class that has the custom attribute associated with one of its members. 
public ref class MyClass1

   [MyAttribute("This is an example attribute.")]
   void MyMethod( int i ){}

int main()
      // Get the type of MyClass1.
      Type^ myType = MyClass1::typeid;

      // Get the members associated with MyClass1. 
      array<MemberInfo^>^myMembers = myType->GetMembers();

      // Display the attributes for each of the members of MyClass1. 
      for ( int i = 0; i < myMembers->Length; i++ )
         // Display the attribute if it is of type MyAttribute. 
         if ( myMembers[ i ]->IsDefined( MyAttribute::typeid, false ) )
            array<Object^>^myAttributes = myMembers[ i ]->GetCustomAttributes( MyAttribute::typeid, false );
            Console::WriteLine( "\nThe attributes of type MyAttribute for the member {0} are: \n", myMembers[ i ] );
            for ( int j = 0; j < myAttributes->Length; j++ )

               // Display the value associated with the attribute.
               Console::WriteLine( "The value of the attribute is : \"{0}\"",
                        (safe_cast<MyAttribute^>(myAttributes[ j ]))->Name );
   catch ( Exception^ e ) 
      Console::WriteLine( "An exception occurred: {0}", e->Message );

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: 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.

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