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.

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