Create an elliptic form using regions

Problem/Question/Abstract:

How to create an elliptic form using regions

Answer:

Add something like the following to your form's OnCreate event handler:

procedure TForm1.FormCreate(Sender: TObject);
var
  Region: HRGN;
begin
  Region := CreateEllipticRgn(0, 0, 300, 300);
  SetWindowRgn(Handle, Region, True);
end;