GC.ReRegisterForFinalize(Object) Metoda

Definice

Obor názvů:

System

Sestavení:

System.Runtime.dll

Sestavení:

mscorlib.dll

Sestavení:

netstandard.dll

Požaduje, aby systém volal finalizátor zadaného objektu, pro který SuppressFinalize(Object) byl dříve volána.

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)

Parametry

obj

Object

Objekt, pro který musí být volána finalizátor.

Výjimky

ArgumentNullException

obj je null.

Příklady

Následující příklad ukazuje, jak použít metodu ReRegisterForFinalize k dokončení objektu podruhé po uvolňování paměti.

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

Poznámky

Metoda ReRegisterForFinalize přidá obj parametr do seznamu objektů, které požadují finalizaci před uvolňováním paměti uvolní objekt. Parametr obj musí být volající této metody.

ReRegisterForFinalize Volání metody nezaručuje, že uvolňování paměti bude volat finalizátor objektu.

Ve výchozím nastavení jsou všechny objekty, které implementují finalizační metody, přidány do seznamu objektů, které vyžadují finalizaci; Objekt však již byl dokončen nebo může být zakázán finalizace voláním SuppressFinalize metody.

Finalizátor může tuto metodu použít k obnovení sebe sama nebo objektu, na který odkazuje.

Viz také

• SuppressFinalize(Object)