关于在COM中使用可选参数的研究[2]

procedure tform1.button1click(sender: tobject);

var

  v: variant;

begin

  v := idispatch(cooptionalparamsdemo.create());

  v.getparams('123');

end;

procedure tform1.button2click(sender: tobject);

var

  aintf: ioptionalparamsdemo;

  v: variant;

begin

  aintf := cooptionalparamsdemo.create();

 // aintf.getparams('', emptyparam, 9, 4);

  v := idispatch(aintf);

 // v.getparams('123', '123', '123', '123');

  v.getparams();

end;

procedure tform1.button3click(sender: tobject);

var

  aintf: ioptionalparamsdemo;

  v: variant;

begin

  aintf := cooptionalparamsdemo.create();

 // aintf.getparams('', emptyparam, 9, 4);

  v := idispatch(aintf);

  v.getparams('123', '123');

 // v.getparams();

end;

procedure tform1.button4click(sender: tobject);

var

  v: variant;

begin

  v := idispatch(cooptionalparamsdemo.create());

  v.getparams('123', '123', 123);

end;

procedure tform1.button5click(sender: tobject);

var

  v: variant;

begin

  v := idispatch(cooptionalparamsdemo.create());

  v.getparams('123', 123, 123, 6);

end;