MemberInfo.IsDefined Method (Type, Boolean)
When overridden in a derived class, indicates whether one or more attributes of the specified type or of its derived types is applied to this member.
Assembly: mscorlib (in mscorlib.dll)
Public MustOverride Function IsDefined ( attributeType As Type, inherit As Boolean ) As Boolean
Parameters
- attributeType
-
Type:
System.Type
The type of custom attribute to search for. The search includes derived types.
- inherit
-
Type:
System.Boolean
true to search this member's inheritance chain to find the attributes; otherwise, false. This parameter is ignored for properties and events; see Remarks.
Return Value
Type: System.Booleantrue if one or more instances of attributeType or any of its derived types is applied to this member; otherwise, false.
This method ignores the inherit parameter for properties and events. To search the inheritance chain for attributes on properties and events, use the appropriate overloads of the Attribute.IsDefined method.
Note |
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In the .NET Framework version 2.0, this method returns true if a type, method, or constructor has security attributes stored in the new metadata format. Assemblies compiled with version 2.0 use this format. Dynamic assemblies and assemblies compiled with earlier versions of the .NET Framework use the old XML format. See Emitting Declarative Security Attributes. |
The following example determines whether the specified attribute is applied to the specified member.
Imports System Imports System.Reflection Imports Microsoft.VisualBasic ' Define a custom attribute with one named parameter. <AttributeUsage(AttributeTargets.All)> Public Class MyAttribute Inherits Attribute Private myName As String Public Sub New(ByVal name As String) myName = name End Sub 'NewNew Public ReadOnly Property Name() As String Get Return myName End Get End Property End Class 'MyAttribute ' Define a class that has the custom attribute associated with one of its members. Public Class MyClass1 <MyAttribute("This is an example attribute.")> Public Sub MyMethod(ByVal i As Integer) Return End Sub 'MyMethod End Class 'MyClass1 Public Class MemberInfo_GetCustomAttributes_IsDefined Public Shared Sub Main() Try ' Get the type of MyClass1. Dim myType As Type = GetType(MyClass1) ' Get the members associated with MyClass1. Dim myMembers As MemberInfo() = myType.GetMembers() ' Display the attributes for each of the members of MyClass1. Dim i As Integer For i = 0 To myMembers.Length - 1 ' Display the attribute if it is of type MyAttribute. If myMembers(i).IsDefined(GetType(MyAttribute), False) Then Dim myAttributes As [Object]() = myMembers(i).GetCustomAttributes(GetType(MyAttribute), False) Console.WriteLine(ControlChars.Cr + "The attributes of type MyAttribute for the member {0} are: " + ControlChars.Cr, myMembers(i)) Dim j As Integer For j = 0 To myAttributes.Length - 1 ' Display the value associated with the attribute. Console.WriteLine("The value of the attribute is : ""{0}""", CType(myAttributes(j), MyAttribute).Name) Next j End If Next i Catch e As Exception Console.WriteLine("An exception occurred: {0}", e.Message) End Try End Sub 'Main End Class 'MemberInfo_GetCustomAttributes_IsDefined
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
