CA2220: Finalizers should call base class finalizer

 

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The latest version of this topic can be found at CA2220: Finalizers should call base class finalizer.

TypeName|FinalizersShouldCallBaseClassFinalizer|
|CheckId|CA2220|
|Category|Microsoft.Usage|
|Breaking Change|Non Breaking|

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

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.

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

Do not suppress 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.

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
   
      Protected Overrides Sub Finalize()
          Try
              Dispose(False)
          Finally
              MyBase.Finalize()
          End Try
      End Sub
   
  End Class
  
End Namespace

Dispose Pattern

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