MethodBase.IsFinal Property

 

Gets a value indicating whether this method is final.

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

Public ReadOnly Property IsFinal As Boolean

Property Value

Type: System.Boolean

true if this method is final; otherwise, false.

To determine if a method is overridable, it is not sufficient to check that IsVirtual is true. For a method to be overridable, IsVirtual must be true and IsFinal must be false. For example, a method might be non-virtual, but it implements an interface method. The common language runtime requires that all methods that implement interface members must be marked as virtual; therefore, the compiler marks the method virtual final. So there are cases where a method is marked as virtual but is still not overridable.

To establish with certainty whether a method is overridable, use code such as this:

if (MethodInfo.IsVirtual && !MethodInfo.IsFinal)

If IsVirtual is false or IsFinal is true, then the method cannot be overridden.

The following example displays false for IsFinal, which might lead you to think that MyMethod is overridable. The code prints false even though MyMethod is not marked virtual and thus cannot be overridden.

Imports System
Imports System.Reflection
Imports Microsoft.VisualBasic

Public Class MyClass1

    Public Sub MyMethod()
    End Sub

    Public Shared Sub Main()
        Dim m As MethodBase = GetType(MyClass1).GetMethod("MyMethod")
        Console.WriteLine("The IsFinal property value of MyMethod is {0}.", m.IsFinal)
        Console.WriteLine("The IsVirtual property value of MyMethod is {0}.", m.IsVirtual)
    End Sub
End Class

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
Return to top
Show: