procedure TForm1.RoundControl(Control: TWinControl; arc1, arc2 :Integer);
var
  R: TRect;
  Rgn: HRGN;
begin
  with Control do
  begin
    R := Control.ClientRect;
    Rgn := CreateRoundRectRgn(R.Left, R.Top, R.Right, R.Bottom, arc1, arc2);
    //Perform(EM_GETRECT, 0, LParam(@R));
    InflateRect(R, -5, -5);       //缩小R 5
    Perform(EM_SETRECTNP, 0, LParam(@R));  //消息等于EM_SETRECT,但是不会发生重绘事件
    SetWindowRgn(Control.Handle, Rgn, True);
    Invalidate;
    {-------------
    Perform(EM_SETRECT, 0, LParam(@R));
    ----------------------}
  end;
  //传入控件的name和两个弧度就可以设置控件的圆角效果
end;