Changing component class at run-time on demand

This is easier as thought (thanks to Hallvard’s Blog – Hack#14: Changing the class of an object at run-time):

procedure PatchInstanceClass(Instance: TObject; NewClass: TClass);
type
  PClass = ^TClass;
begin
  if Assigned(Instance) and Assigned(NewClass)
    and NewClass.InheritsFrom(Instance.ClassType)
    and (NewClass.InstanceSize = Instance.InstanceSize) then
  begin
    PClass(Instance)^ := NewClass;
  end;
end;

type
  TMyButton = class(TButton)
  public
    procedure Click; override;
  end;

procedure TMyButton.Click;
begin
  ShowMessage('Click!');
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  PatchInstanceClass(Button1, TMyButton);
end;