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Attribute::GetCustomAttributes Method (ParameterInfo, Type, Boolean)

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

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

public:
static array<Attribute^>^ GetCustomAttributes(
	ParameterInfo^ element, 
	Type^ attributeType, 
	bool inherit
)

Parameters

element
Type: System.Reflection::ParameterInfo

An object derived from the ParameterInfo class that describes a parameter of a member of a class.

attributeType
Type: System::Type

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

inherit
Type: System::Boolean

If true, specifies to also search the ancestors of element for custom attributes.

Return Value

Type: array<System::Attribute>
An Attribute array that contains the custom attributes of type attributeType applied to element, or an empty array if no such custom attributes exist.

ExceptionCondition
ArgumentNullException

element or attributeType is nullptr.

ArgumentException

attributeType is not derived from Attribute.

TypeLoadException

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 namespace System;
using namespace System::Reflection;
using namespace System::ComponentModel;

namespace CustAttrs5CS
{
   public ref class AClass
   {
   public:
      void ParamArrayAndDesc(
         // Add ParamArray and Description attributes.
         [Description("This argument is a ParamArray")]
         array<Int32>^args )
      {}
   };

   ref class DemoClass
   {
   public:
      static void Main()
      {
         // Get the Class type to access its metadata.
         Type^ clsType = AClass::typeid;

         // Get the type information for the method.
         MethodInfo^ mInfo = clsType->GetMethod( "ParamArrayAndDesc" );
         if ( mInfo != nullptr )
         {
            // Get the parameter information. 
            array<ParameterInfo^>^pInfo = mInfo->GetParameters();
            if ( pInfo != nullptr )
            {
               // Iterate through all the attributes for the parameter.
               System::Collections::IEnumerator^ myEnum4 = Attribute::GetCustomAttributes( pInfo[ 0 ] )->GetEnumerator();
               while ( myEnum4->MoveNext() )
               {
                  Attribute^ attr = safe_cast<Attribute^>(myEnum4->Current);

                  // Check for the ParamArray attribute. 
                  if ( attr->GetType() == ParamArrayAttribute::typeid )
                                    Console::WriteLine( "Parameter {0} for method {1} " 
                  "has the ParamArray attribute.", pInfo[ 0 ]->Name, mInfo->Name );
                  // Check for the Description attribute. 
                  else 

                  // Check for the Description attribute. 
                  if ( attr->GetType() == DescriptionAttribute::typeid )
                  {
                     Console::WriteLine( "Parameter {0} for method {1} " 
                     "has a description attribute.", pInfo[ 0 ]->Name, mInfo->Name );
                     Console::WriteLine( "The description is: \"{0}\"", (dynamic_cast<DescriptionAttribute^>(attr))->Description );
                  }
               }
            }
         }
      }
   };
}

/*
 * 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: 4.6, 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

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8

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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