IsDefined Method

Assembly.IsDefined Method (Type, Boolean)


Indicates whether or not a specified attribute has been applied to the assembly.

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

public virtual bool IsDefined(
	Type attributeType,
	bool inherit


Type: System.Type

The type of the attribute to be checked for this assembly.

Type: System.Boolean

This argument is ignored for objects of this type.

Return Value

Type: System.Boolean

true if the attribute has been applied to the assembly; otherwise, false.

Exception Condition

attributeType is null.


attributeType uses an invalid type.

The following code example applies the AssemblyTitleAttribute attribute to an assembly and then uses IsDefined to indicate whether it was applied. It also tests an attribute that was not applied.

using System;
using System.Reflection;

// Set an assembly attribute.
[assembly:AssemblyTitleAttribute("A title example")]

// Note that the suffix "Attribute" can be omitted:
// [assembly:AssemblyTitle("A title example")]

public class Test {

    public static void Main() {

        // Get the assembly that is executing this method.
        Assembly asm = Assembly.GetCallingAssembly();

        // Get the attribute type just defined.
        Type aType = typeof(AssemblyTitleAttribute);
        Console.WriteLine(asm.IsDefined(aType, false));

        // Try an attribute not defined.
        aType = typeof(AssemblyVersionAttribute);
        Console.WriteLine(asm.IsDefined(aType, false));
//  This code example produces the following output:
//  True
//  False

.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Available since 2.0
Windows Phone Silverlight
Available since 7.0
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