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IsDefined Method (ParameterInfo, Type)

Attribute::IsDefined Method (ParameterInfo, Type)

Determines whether any custom attributes are applied to a method parameter. Parameters specify the method parameter, and the type of the custom attribute to search for.

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

public:
static bool IsDefined(
	ParameterInfo^ element, 
	Type^ attributeType
)

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.

Return Value

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

ExceptionCondition
ArgumentNullException

element or attributeType is nullptr.

ArgumentException

attributeType is not derived from Attribute.

The ancestors of element are searched for custom attributes.

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

using namespace System;
using namespace System::Reflection;

namespace IsDef5CS
{
   public ref class TestClass
   {
   public:

      // Assign a ParamArray attribute to the parameter using the keyword. 
      void Method1(... array<String^>^args ){}

   };

   ref class DemoClass
   {
   public:
      static void Main()
      {

         // Get the class type to access its metadata.
         Type^ clsType = TestClass::typeid;

         // Get the MethodInfo object for Method1.
         MethodInfo^ mInfo = clsType->GetMethod( "Method1" );

         // Get the ParameterInfo array for the method parameters. 
         array<ParameterInfo^>^pInfo = mInfo->GetParameters();
         if ( pInfo != nullptr )
         {

            // See if the ParamArray attribute is defined. 
            bool isDef = Attribute::IsDefined( pInfo[ 0 ], ParamArrayAttribute::typeid );

            // Display the result.
            Console::WriteLine( "The ParamArray attribute {0} defined for " 
            "parameter {1} of method {2}.", isDef ? (String^)"is" : "is not", pInfo[ 0 ]->Name, mInfo->Name );
         }
         else
                  Console::WriteLine( "The parameters information could " 
         "not be retrieved for method {0}.", mInfo->Name );
      }

   };

}

/*
 * Output:
 * The ParamArray attribute is defined for parameter args of method Method1.
 */

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0, 2.0, 1.0

.NET for Windows Phone apps

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

Portable Class Library

Supported in: Portable Class Library
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