Information
The topic you requested is included in another documentation set. For convenience, it's displayed below. Choose Switch to see the topic in its original location.

Attribute.IsDefined Method (Assembly, Type)

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 static bool IsDefined (
	Assembly element,
	Type attributeType
)
public static boolean IsDefined (
	Assembly element, 
	Type attributeType
)
public static function IsDefined (
	element : Assembly, 
	attributeType : Type
) : boolean

Parameters

element

An object derived from the Assembly class that describes a reusable collection of modules.

attributeType

The type, or a base type, of the custom attribute to search for.

Return Value

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

Exception typeCondition

ArgumentNullException

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

ArgumentException

attributeType is not derived from Attribute.

The following code example illustrates the use of IsDefined, taking an Assembly as a parameter.

using System;
using System.Reflection;

// Add an AssemblyDescription attribute
[assembly: AssemblyDescription("A sample description")]
namespace IsDef1CS
{
    public class DemoClass
    {
        static void Main(string[] args)
        {
            // Get the class type to access its metadata.
            Type clsType = typeof(DemoClass);
            // Get the assembly object.
            Assembly assy = clsType.Assembly;
            // Store the assembly's name.
            String assyName = assy.GetName().Name;
            // See if the Assembly Description is defined.
            bool isdef = Attribute.IsDefined(assy, 
                typeof(AssemblyDescriptionAttribute));
            if (isdef)
            {
                // Affirm that the attribute is defined.
                Console.WriteLine("The AssemblyDescription attribute " +
                    "is defined for assembly {0}.", assyName);
                // Get the description attribute itself.
                AssemblyDescriptionAttribute adAttr = 
                    (AssemblyDescriptionAttribute)Attribute.GetCustomAttribute(
                    assy, typeof(AssemblyDescriptionAttribute));
                // Display the description.
                if (adAttr != null)
                    Console.WriteLine("The description is \"{0}\".", 
                        adAttr.Description);
                else
                    Console.WriteLine("The description could not " +
                        "be retrieved.");            
            }
            else
                Console.WriteLine("The AssemblyDescription attribute is not " +
                    "defined for assembly {0}.", assyName);
        }
    }
}

/*
 * Output:
 * The AssemblyDescription attribute is defined for assembly IsDef1CS.
 * The description is "A sample description".
 */

package IsDef1JSL; 
import System.*;
import System.Reflection.*;

// Add an AssemblyDescription attribute
/** @assembly AssemblyDescription("A sample description")
 */
class DemoClass
{
    public static void main(String[] args)
    {
        // Get the class type to access its metadata.
        Type clsType = DemoClass.class.ToType();
        // Get the assembly object.
        Assembly assy = clsType.get_Assembly();
        // Store the assembly's name.
        String assyName = assy.GetName().get_Name();
        //Type assyType = assy.GetType();
        // See if the Assembly Description is defined.
        boolean isdef = Attribute.IsDefined(assy, 
            AssemblyDescriptionAttribute.class.ToType());
        if (isdef) {
            // Affirm that the attribute is defined.
            Console.WriteLine("The AssemblyDescription attribute " 
                + "is defined for assembly {0}.", assyName);
            // Get the description attribute itself.
            AssemblyDescriptionAttribute adAttr = (AssemblyDescriptionAttribute)
                (Attribute.GetCustomAttribute(assy, 
                AssemblyDescriptionAttribute.class.ToType()));
            // Display the description.
            if (adAttr != null) {
                Console.WriteLine("The description is \"{0}\".", 
                    adAttr.get_Description());
            }
            else {
                Console.WriteLine("The description could not " 
                    + "be retrieved.");
            }
        }
        else {
            Console.WriteLine("The AssemblyDescription attribute is not " 
                + "defined for assembly {0}.", assyName);
        }
    } //main
} //DemoClass

/*
   Output:
   The AssemblyDescription attributeis defined for assembly IsDef1JSL.
   The description is "A sample description".
*/

import System;
import System.Reflection;

// Add an AssemblyDescription attribute
[assembly: AssemblyDescription("A sample description")]

package IsDef1JS
{
    class DemoClass
    {
        static function Main() : void 
        {
            // Get the class type to access its metadata.
            var clsType : Type = DemoClass;
            // Get the assembly object.
            var assy : Assembly = clsType.Assembly;
            // Store the assembly's name.
            var assyName : String = assy.GetName().Name;
            //Type assyType = assy.GetType();
            // See if the Assembly Description is defined.
            var isdef : boolean = Attribute.IsDefined(assy, AssemblyDescriptionAttribute);
            if (isdef)
            {
                // Affirm that the attribute is defined.
                Console.WriteLine("The AssemblyDescription attribute " +
	                "is defined for assembly {0}.", assyName);
                // Get the description attribute itself.
                var adAttr : AssemblyDescriptionAttribute = 
	                AssemblyDescriptionAttribute(Attribute.GetCustomAttribute(
	                assy, AssemblyDescriptionAttribute));
                // Display the description.
                if (adAttr != null)
	                Console.WriteLine("The description is \"{0}\".", 
		                adAttr.Description);
                else
	                Console.WriteLine("The description could not " +
		                "be retrieved.");			
            }
            else
                Console.WriteLine("The AssemblyDescription attribute is not " +
	                "defined for assembly {0}.", assyName);
        }
    }
}

IsDef1JS.DemoClass.Main();

/*
 * Output:
 * The AssemblyDescription attributeis defined for assembly IsDef1CS.
 * The description is "A sample description".
 */

Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

Community Additions

Show:
© 2014 Microsoft