TForm.OnDestroy Event

Occurs when the form is destroyed.

Pascal

property OnDestroy: TNotifyEvent;

C++

__property TNotifyEvent OnDestroy;

Description

Use OnDestroy to perform special processing when the form is destroyed. Either implement this event or override the destructor of the class, but not both. This event should destroy any objects created in the OnCreate event.

C++ Examples:

Copy Code

/*
The following code allocates a TBitmap object that is used
by the application when the main form is first created. The
OnDestroy method frees the bitmap as the application shuts
down.
*/
Graphics::TBitmap *LogoBmp;
void __fastcall TForm1::FormCreate(TObject *Sender)
{
  LogoBmp = new Graphics::TBitmap();
  LogoBmp->LoadFromFile("../FACTORY.BMP");
}

void __fastcall TForm1::FormDestroy(TObject *Sender)
{
  delete LogoBmp;
}

void __fastcall TForm1::FormPaint(TObject *Sender)
{
  Canvas->Brush->Bitmap = LogoBmp;
  Canvas->FillRect(Rect(0,0,100,100));
}

Delphi Examples:

Copy Code

{
The following code explicitly allocates memory for a pointer
in the OnCreate event of Form1, then releases the memory in
the OnDestroy event. Assume that MyPtr is a Pointer type
field of TForm1.
} 
procedure TForm1.FormCreate(Sender: TObject);
begin
  New(MyPtr);
end;

procedure TForm1.FormDestroy(Sender: TObject);
begin
  Dispose(MyPtr);
end;