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 Booleanpublic abstract bool IsDefined(
Type attributeType,
bool inherit
)public:
virtual bool IsDefined(
Type^ attributeType,
bool inherit
) abstractabstract IsDefined :
attributeType:Type *
inherit:bool -> bool
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: Systemtrue if one or more instances of attributeType or any of its derived types is applied to this member; otherwise, false.
Implements
ICustomAttributeProvider_MemberInfo
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
Note |
|---|
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 'New
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
using System;
using System.Reflection;
// Define a custom attribute with one named parameter.
[AttributeUsage(AttributeTargets.All)]
public class MyAttribute : Attribute
{
private string myName;
public MyAttribute(string name)
{
myName = name;
}
public string Name
{
get
{
return myName;
}
}
}
// Define a class that has the custom attribute associated with one of its members.
public class MyClass1
{
[MyAttribute("This is an example attribute.")]
public void MyMethod(int i)
{
return;
}
}
public class MemberInfo_GetCustomAttributes_IsDefined
{
public static void Main()
{
try
{
// Get the type of MyClass1.
Type myType = typeof(MyClass1);
// Get the members associated with MyClass1.
MemberInfo[] myMembers = myType.GetMembers();
// Display the attributes for each of the members of MyClass1.
for(int i = 0; i < myMembers.Length; i++)
{
// Display the attribute if it is of type MyAttribute.
if(myMembers[i].IsDefined(typeof(MyAttribute), false))
{
Object[] myAttributes = myMembers[i].GetCustomAttributes(typeof(MyAttribute), false);
Console.WriteLine("\nThe attributes of type MyAttribute for the member {0} are: \n",
myMembers[i]);
for(int j = 0; j < myAttributes.Length; j++)
// Display the value associated with the attribute.
Console.WriteLine("The value of the attribute is : \"{0}\"",
((MyAttribute)myAttributes[j]).Name);
}
}
}
catch(Exception e)
{
Console.WriteLine("An exception occurred: {0}", e.Message);
}
}
}
using namespace System;
using namespace System::Reflection;
// Define a custom attribute with one named parameter.
[AttributeUsage(AttributeTargets::All)]
public ref class MyAttribute: public Attribute
{
private:
String^ myName;
public:
MyAttribute( String^ name )
{
myName = name;
}
property String^ Name
{
String^ get()
{
return myName;
}
}
};
// Define a class that has the custom attribute associated with one of its members.
public ref class MyClass1
{
public:
[MyAttribute("This is an example attribute.")]
void MyMethod( int i ){}
};
int main()
{
try
{
// Get the type of MyClass1.
Type^ myType = MyClass1::typeid;
// Get the members associated with MyClass1.
array<MemberInfo^>^myMembers = myType->GetMembers();
// Display the attributes for each of the members of MyClass1.
for ( int i = 0; i < myMembers->Length; i++ )
{
// Display the attribute if it is of type MyAttribute.
if ( myMembers[ i ]->IsDefined( MyAttribute::typeid, false ) )
{
array<Object^>^myAttributes = myMembers[ i ]->GetCustomAttributes( MyAttribute::typeid, false );
Console::WriteLine( "\nThe attributes of type MyAttribute for the member {0} are: \n", myMembers[ i ] );
for ( int j = 0; j < myAttributes->Length; j++ )
// Display the value associated with the attribute.
Console::WriteLine( "The value of the attribute is : \"{0}\"",
(safe_cast<MyAttribute^>(myAttributes[ j ]))->Name );
}
}
}
catch ( Exception^ e )
{
Console::WriteLine( "An exception occurred: {0}", e->Message );
}
}
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Note