Visual Studio Team System
Finalizers should call base class finalizer

TypeName

FinalizersShouldCallBaseClassFinalizer

CheckId

CA2220

Category

Microsoft.Usage

Breaking Change

NonBreaking

Cause

A type that overrides System.Object.Finalize does not call the Finalize method in its base class.

Rule Description

Finalization must be propagated through the inheritance hierarchy. To ensure this, types must call their base class Finalize method from within their own Finalize method. The C# compiler adds the call to the base class finalizer automatically.

How to Fix Violations

To fix a violation of this rule, call the base type's Finalize method from your Finalize method.

When to Exclude Warnings

Do not exclude a warning from this rule. Some compilers that target the common language runtime insert a call to the base type's finalizer into the Microsoft intermediate language (MSIL). If a warning from this rule is reported, your compiler does not insert the call, and you must add it to your code.

Example

The following Visual Basic example shows a type TypeB that correctly calls the Finalize method in its base class.

Visual Basic
Imports System

Namespace UsageLibrary

    Public Class TypeB
        Inherits TypeA

        Friend Overrides Sub Dispose(ByVal disposing As Boolean)
            Try
                Dispose(False)
            Finally
                MyBase.Finalize()
            End Try
        End Sub 'Dispose
    End Class 'TypeB

End Namespace
See Also

Reference

Implementing Finalize and Dispose to Clean Up Unmanaged Resources

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Community Content

David M. Kean - MSFT
Sample is wrong

The above sample is incorrect, it actually shows the Dispose method rather than the Finalize.

The following is a better example:

[Visual Basic]
 
Public Class TypeB
    Inherits TypeA
 
    Protected Overrides Sub Finalize()
        Try
         Dispose(False)
        Finally
        MyBase.Finalize()
     End Try
End Sub
 
End Class

 

No sample is needed for C#, because, as mentioned above, the C# compiler automatically calls the base class's finalizer, therefore you do not need to do anything.

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