How to Clone a Delphi Form

Creating Delphi objects (forms, components, etc) dynamically, at run-time, is a "standard" coding technique for Delphi developers. Almost every Form that you want to show modally will be created dynamically, displayed to the user and freed from the memory.

Besides instantiating Delphi Forms dynamically, you can decide to create a *clone* of an existing form - by using the TMemoryStream class.

Note: when you create a new clone from an existing form, the clone's OnCreate will not execute.

Here's how:

 procedure FormClone(form : TForm) ;
 var
    ms : TMemoryStream;
    clone : TForm;
 begin
    ms := TMemoryStream.Create;
    try
      ms.WriteComponent(form) ;
      ms.Position := 0;
      clone := TFormClass(form.ClassType).CreateNew(Application) ;
      ms.ReadComponent(clone) ;
 
      clone.Left := form.Left + 10;
      clone.Top := form.Top + 10;
      clone.Show;
    finally
      ms.Free;
    end;
 end;
 
 //Usage
 procedure TForm1.Button1Click(Sender: TObject) ;
 begin
    FormClone(Form1) ;
 end;

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