Attribute.IsDefined Method (Assembly, Type)

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

Determines whether any custom attributes are applied to an assembly. Parameters specify the assembly, and the type of the custom attribute to search for.

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


Public Shared Function IsDefined ( _
    element As Assembly, _
    attributeType As Type _
) As Boolean
public static bool IsDefined(
    Assembly element,
    Type attributeType


  • attributeType
    Type: System..::.Type
    The type, or a base type, of the custom attribute to search for.

Return Value

Type: System..::.Boolean
true if a custom attribute of type attributeType is applied to element; otherwise, false.


Exception Condition

element or attributeType is nullNothingnullptra null reference (Nothing in Visual Basic).


attributeType is not derived from Attribute.

Version Information

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0


Windows Phone

See Also


Attribute Class

IsDefined Overload

System Namespace