GC.ReRegisterForFinalize(Object) Metodo

public:
 static void ReRegisterForFinalize(System::Object ^ obj);

public static void ReRegisterForFinalize (object obj);

static member ReRegisterForFinalize : obj -> unit

Public Shared Sub ReRegisterForFinalize (obj As Object)

Parametri

Eccezioni

Esempio

Nell'esempio seguente viene illustrato come usare il ReRegisterForFinalize metodo per finalizzare un oggetto una seconda volta dopo Garbage Collection.

using namespace System;
ref class MyFinalizeObject
{
public:
   static MyFinalizeObject^ currentInstance = nullptr;

private:
   bool hasFinalized;

public:
   MyFinalizeObject()
   {
      hasFinalized = false;
   }

   ~MyFinalizeObject()
   {
      if ( hasFinalized == false )
      {
         Console::WriteLine( "First finalization" );
         
         // Put this object back into a root by creating
         // a reference to it.
         MyFinalizeObject::currentInstance = this;
         
         // Indicate that this instance has finalized once.
         hasFinalized = true;
         
         // Place a reference to this object back in the
         // finalization queue.
         GC::ReRegisterForFinalize( this );
      }
      else
      {
         Console::WriteLine( "Second finalization" );
      }
   }

};

int main()
{
   
   // Create a MyFinalizeObject.
   MyFinalizeObject^ mfo = gcnew MyFinalizeObject;
   
   // Release the reference to mfo.
   mfo = nullptr;
   
   // Force a garbage collection.
   GC::Collect();
   
   // At this point mfo will have gone through the first Finalize.
   // There should now be a reference to mfo in the static
   // MyFinalizeObject::currentInstance field.  Setting this value
   // to 0 and forcing another garbage collection will now
   // cause the object to Finalize permanently.
   MyFinalizeObject::currentInstance = nullptr;
   GC::Collect();
}

using System;

namespace ReRegisterForFinalizeExample
{
    class MyMainClass
    {
        static void Main()
        {
            // Create a MyFinalizeObject.
            MyFinalizeObject mfo = new MyFinalizeObject();

            // Release the reference to mfo.
            mfo = null;

            // Force a garbage collection.
            GC.Collect();

            // At this point mfo will have gone through the first Finalize.
            // There should now be a reference to mfo in the static
            // MyFinalizeObject.currentInstance field.  Setting this value
            // to null and forcing another garbage collection will now
            // cause the object to Finalize permanently.
            MyFinalizeObject.currentInstance = null;
            GC.Collect();
        }
    }

    class MyFinalizeObject
    {
        public static MyFinalizeObject currentInstance = null;
        private bool hasFinalized = false;

        ~MyFinalizeObject()
        {
            if(hasFinalized == false)
            {
                Console.WriteLine("First finalization");

                // Put this object back into a root by creating
                // a reference to it.
                MyFinalizeObject.currentInstance = this;

                // Indicate that this instance has finalized once.
                hasFinalized = true;

                // Place a reference to this object back in the
                // finalization queue.
                GC.ReRegisterForFinalize(this);
            }
            else
            {
                Console.WriteLine("Second finalization");
            }
        }
    }
}

open System

[<AllowNullLiteral>]
type MyFinalizeObject() =
    let mutable hasFinalized = false
    
    static member val CurrentInstance = null with get, set

    override this.Finalize() =
        if hasFinalized then
            printfn "First finalization"

            // Put this object back into a root by creating a reference to it.
            MyFinalizeObject.CurrentInstance <- this

            // Indicate that this instance has finalized once.
            hasFinalized <- true

            // Place a reference to this object back in the finalization queue.
            GC.ReRegisterForFinalize this
        else 
            printfn "Second finalization"

// Create a MyFinalizeObject.
let mutable mfo = MyFinalizeObject()

// Release the reference to mfo.
mfo <- null

// Force a garbage collection.
GC.Collect()

// At this point mfo will have gone through the first Finalize.
// There should now be a reference to mfo in the static
// MyFinalizeObject.CurrentInstance property. Setting this value
// to null and forcing another garbage collection will now
// cause the object to Finalize permanently.
MyFinalizeObject.CurrentInstance <- null
GC.Collect()

Namespace ReRegisterForFinalizeExample
    Class MyMainClass
        Shared Sub Main()
            'Create a MyFinalizeObject.
            Dim mfo As New MyFinalizeObject()

            'Release the reference to mfo.
            mfo = Nothing

            'Force a garbage collection.
            GC.Collect()

            'At this point mfo will have gone through the first Finalize.
            'There should now be a reference to mfo in the static
            'MyFinalizeObject.currentInstance field.  Setting this value
            'to null and forcing another garbage collection will now
            'cause the object to Finalize permanently.
            MyFinalizeObject.currentInstance = Nothing
            GC.Collect()
        End Sub
    End Class

    Class MyFinalizeObject
        Public Shared currentInstance As MyFinalizeObject = Nothing
        Private hasFinalized As Boolean = False

        Protected Overrides Sub Finalize()
            If hasFinalized = False Then
                Console.WriteLine("First finalization")

                'Put this object back into a root by creating
                'a reference to it.
                MyFinalizeObject.currentInstance = Me

                'Indicate that this instance has finalized once.
                hasFinalized = True

                'Place a reference to this object back in the
                'finalization queue.
                GC.ReRegisterForFinalize(Me)
            Else
                Console.WriteLine("Second finalization")
            End If
            MyBase.Finalize()
        End Sub
    End Class
End Namespace

Commenti

Il ReRegisterForFinalize metodo aggiunge il obj parametro all'elenco di oggetti che richiedono la finalizzazione prima che Garbage Collector libera l'oggetto. Il obj parametro deve essere il chiamante di questo metodo.

La chiamata al ReRegisterForFinalize metodo non garantisce che il Garbage Collector chiamerà il finalizzatore di un oggetto.

Per impostazione predefinita, tutti gli oggetti che implementano i finalizzatori vengono aggiunti all'elenco di oggetti che richiedono la finalizzazione; Tuttavia, un oggetto potrebbe essere già stato finalizzato o potrebbe avere disabilitato la finalizzazione chiamando il SuppressFinalize metodo .

Un finalizzatore può usare questo metodo per riattivare se stesso o un oggetto a cui fa riferimento.

Si applica a

Vedi anche

• SuppressFinalize(Object)