RichEdit选中文字右键菜单的实现

procedure TForm1.RichEdit1MouseDown(Sender: TObject; Button: TMouseButton;
 Shift: TShiftState; X, Y: Integer);
var
 vPoint: TPoint;
begin
 if Button <> mbRight then Exit;
 vPoint := Point(X, Y);
 X := SendMessage(RichEdit1.Handle, EM_CHARFROMPOS,0,
    Integer(@vPoint)) and $0000FFFF;// 得到鼠标点击字符位置
 if (X >= RichEdit1.SelStart) and
    (X <= RichEdit1.SelStart + RichEdit1.SelLength) then
    ShowMessage(RichEdit1.SelText);
end;