SetWindowLong(Edit1.Handle, GWL_STYLE, GetWindowLong(Edit1.Handle, GWL_STYLE) or ES_CENTER);
Edit1.Invalidate;
//如果右对齐,将ES_CENTER变成ES_RIGHT
//(转自http://blog.csdn.net/wudi_1982/article/details/1205472)
//限制输入位数为2
Edit1.MaxLength := 2;
//只允许输入数字
procedure TForm1.Edit1KeyPress(Sender: TObject; var Key: Char);
begin
if not (key in ['0'..'9', #3, #13, #8, #22]) then
key := #0;
end;