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Attribute.GetCustomAttributes Method (ParameterInfo, Boolean)

Retrieves an array of the custom attributes applied to a method parameter. Parameters specify the method parameter, and whether to search ancestors of the method parameter.

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

public static Attribute[] GetCustomAttributes(
	ParameterInfo element,
	bool inherit


Type: System.Reflection.ParameterInfo
An object derived from the ParameterInfo class that describes a parameter of a member of a class.
Type: System.Boolean
If true, specifies to also search the ancestors of element for custom attributes.

Return Value

Type: System.Attribute[]
An Attribute array that contains the custom attributes applied to element, or an empty array if no such custom attributes exist.


The Member property of element is null.


element is null.


A custom attribute type cannot be loaded.

If element represents a parameter in a method of a derived type, the return value includes the inheritable custom attributes applied to the same parameter in the overridden base methods.

The following code example demonstrates the use of GetCustomAttributes, taking a ParameterInfo as a parameter.

using System;
using System.Reflection;
using System.ComponentModel;

namespace CustAttrs5CS {
    public class AClass {
        public void ParamArrayAndDesc(
            // Add ParamArray (with the keyword) and Description attributes.
            [Description("This argument is a ParamArray")]
            params int[] args)

    class DemoClass {
        static void Main(string[] args) {
            // Get the Class type to access its metadata.
            Type clsType = typeof(AClass);
            // Get the type information for the method.
            MethodInfo mInfo = clsType.GetMethod("ParamArrayAndDesc");
            if (mInfo != null) {
                // Get the parameter information.
                ParameterInfo[] pInfo = mInfo.GetParameters();
                if (pInfo != null) {
                    // Iterate through all the attributes for the parameter.
                    foreach(Attribute attr in 
                        Attribute.GetCustomAttributes(pInfo[0])) {
                        // Check for the ParamArray attribute.
                        if (attr.GetType() == typeof(ParamArrayAttribute))
                            Console.WriteLine("Parameter {0} for method {1} " +
                                "has the ParamArray attribute.",
                                pInfo[0].Name, mInfo.Name);
                        // Check for the Description attribute.
                        else if (attr.GetType() == 
                            typeof(DescriptionAttribute)) {
                            Console.WriteLine("Parameter {0} for method {1} " +
                                "has a description attribute.",
                                pInfo[0].Name, mInfo.Name);
                            Console.WriteLine("The description is: \"{0}\"",

 * Output:
 * Parameter args for method ParamArrayAndDesc has a description attribute.
 * The description is: "This argument is a ParamArray"
 * Parameter args for method ParamArrayAndDesc has the ParamArray attribute.

.NET Framework

Supported in: 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

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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