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ParameterInfo.GetCustomAttributes Method (Boolean)

Gets all the custom attributes defined on this parameter.

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

public virtual Object[] GetCustomAttributes(
	bool inherit
)

Parameters

inherit
Type: System.Boolean

This argument is ignored for objects of this type. See Remarks.

Return Value

Type: System.Object[]
An array that contains all the custom attributes applied to this parameter.

Implements

ICustomAttributeProvider.GetCustomAttributes(Boolean)

ExceptionCondition
TypeLoadException

A custom attribute type could not be loaded.

This method ignores the inherit parameter. To search the inheritance chain for attributes on parameters, use the appropriate overloads of the Attribute.GetCustomAttributes method.

The following example shows how custom attributes that have been applied to the parameters of methods can be retrieved at run time. The example defines a custom attribute named MyAttribute that can be applied to parameters. The example then defines a class named MyClass with a method named MyMethod, and applies MyAttribute to a parameter of the method.

When the example is run, it uses the GetCustomAttributes(Boolean) method to retrieve the custom attributes that have been applied to all parameters of all methods in MyClass, and displays them at the console.

using System;
using System.Reflection;

// Define a custom attribute with one named parameter.
[AttributeUsage(AttributeTargets.Parameter)]
public class MyAttribute : Attribute
{
    private string myName;
    public MyAttribute(string name)
    {
        myName = name;
    }
    public string Name 
    {
        get 
        {
            return myName;
        }
    }
}

// Define a class which has a custom attribute associated with one of the  
// parameters of a method.  
public class MyClass1
{
    public void MyMethod(
        [MyAttribute("This is an example parameter attribute")]
        int i)
    {
        return;
    }
}

public class MemberInfo_GetCustomAttributes 
{
    public static void Main()
    {
        // Get the type of the class 'MyClass1'.
        Type myType = typeof(MyClass1);
        // Get the members associated with the class 'MyClass1'.
        MethodInfo[] myMethods = myType.GetMethods();

        // Display the attributes for each of the parameters of each method of the class 'MyClass1'. 
        for(int i = 0; i < myMethods.Length; i++)
        {
            // Get the parameters for the method.
            ParameterInfo[] myParameters = myMethods[i].GetParameters();

            if (myParameters.Length > 0)
            {
                Console.WriteLine("\nThe parameters for the method {0} that have custom attributes are :", myMethods[i]);
                for(int j = 0; j < myParameters.Length; j++)
                {
                    // Get the attributes of type 'MyAttribute' for each parameter.
                    Object[] myAttributes = myParameters[j].GetCustomAttributes(typeof(MyAttribute), false);

                    if (myAttributes.Length > 0)
                    {
                        Console.WriteLine("Parameter {0}, name = {1}, type = {2} has attributes: ", 
                            myParameters[j].Position, myParameters[j].Name, myParameters[j].ParameterType);
                        for(int k = 0; k < myAttributes.Length; k++)
                        {
                            Console.WriteLine("\t{0}", myAttributes[k]);
                        }
                    }
                }
            }
        }  
    }
}
/* This code example produces the following output:

The parameters for the method Void MyMethod(Int32) that have custom attributes are :
Parameter 0, name = i, type = System.Int32 has attributes:
        MyAttribute

The parameters for the method Boolean Equals(System.Object) that have custom attributes are :
 */

.NET Framework

Supported in: 4.5.2, 4.5.1, 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

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone 8, Silverlight 8.1

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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