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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)
'Declaration
Public Shared Function GetCustomAttributes ( _
	element As ParameterInfo, _
	inherit As Boolean _
) As Attribute()

Parameters

element
Type: System.Reflection.ParameterInfo

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

inherit
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.
ExceptionCondition
ArgumentException

The Member property of element is null.

ArgumentNullException

element is Nothing.

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.

Imports System
Imports System.Reflection
Imports System.ComponentModel

Module DemoModule
    Public Class AClass
        ' Add Description and ParamArray (with the keyword) attributes. 
        Public Sub ParamArrayAndDesc( _
            <Description("This argument is a ParamArray")> _
            ByVal ParamArray args() As Integer)
        End Sub 
    End Class 

    Sub Main()
        ' Get the Class type to access its metadata. 
        Dim clsType As Type = GetType(AClass)
        ' Get the type information for the method. 
        Dim mInfo As MethodInfo = clsType.GetMethod("ParamArrayAndDesc")
        ' Get the Parameter information for the method. 
        Dim pInfo() As ParameterInfo = mInfo.GetParameters()
        Dim attr As Attribute
        ' Iterate through each attribute of the parameter. 
        For Each attr In Attribute.GetCustomAttributes(pInfo(0))
            ' Check for the ParamArray attribute. 
            If TypeOf attr Is ParamArrayAttribute Then 
                ' Convert the attribute to access its data. 
                Dim paAttr As ParamArrayAttribute = _
                    CType(attr, ParamArrayAttribute)
                Console.WriteLine("Parameter {0} has the " + _
                    "ParamArray attribute.", pInfo(0).Name)
            ' Check for the Description attribute. 
            ElseIf TypeOf attr Is DescriptionAttribute Then 
                ' Convert the attribute to access its data. 
                Dim descAttr As DescriptionAttribute = _
                    CType(attr, DescriptionAttribute)
                Console.WriteLine("Parameter {0} has a description " + _
                    "attribute. The description is:", pInfo(0).Name)
                Console.WriteLine(descAttr.Description)
            End If 
        Next 
    End Sub 
End Module 

' Output: 
' Parameter args has a description attribute. The description is: 
' This argument is a ParamArray 
' Parameter args has the ParamArray attribute.

.NET Framework

Supported in: 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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