delphi 串口的打开与关闭

Delphi 打开串口与关闭串口

 procedure TForm1.btn1Click(Sender: TObject);
 begin
   cm1.CommName:=cbb1.Text;
   cm1.BaudRate:=strtoint(cbb2.Items[cbb2.ItemIndex]);
   case cbb3.ItemIndex of
     :cm1.ByteSize:=_5;
     :cm1.ByteSize:=_6;
     :cm1.ByteSize:=_7;
     :cm1.ByteSize:=_8;
   end;

   case cbb4.ItemIndex of
     :cm1.StopBits:=_1;
     :cm1.StopBits:=_1_5;
     :cm1.StopBits:=_2;
   end;

   cm1.StopComm;//关闭串口
   try
     cm1.StartComm;//打开串口
   except
     ShowMessage('串口打开失败！');
     Exit;
   end;

   Delay();//延时
   ShowMessage('成功打开串口：');
 end;