DELPHI中用MSCOMM实现串口通信

//发送数据
procedure senddata(astr:string);
  var k:integer;
      p:pchar;
      achr:array of char;
begin
  setlength(sbuf,length(astr));
  setlength(achr,length(astr));
  p:=pchar(astr);
  for k:=0 to length(astr)-1 do
  begin
    achr[k]:=p^;
    sbuf[k]:=ord(achr[k]);
    p:=p+1;
  end;
  if frmMain.mscomm1.PortOpen=true then
  begin
    frmMain.mscomm1.Output:=sbuf;
  end;
  sleep(200);
end;
 
这是发送字符串的代码,如果是发送十六进制,直接用一个array of byte就行了,更加简单,接收类似.
//接收数据
procedure TfrmMain.MSComm1Comm(Sender: TObject);
var
  v:Olevariant;
  astr:string;
  in_array:array of byte;
  xtemp : Olevariant;
  xScr : array of byte;
  i, j : Integer;
  xnNAK, xnRSD : Integer;
  xRecData: String;
begin
  i:=msComm1.InBufferCount;

  if i=0 then
      Exit;

  if msComm1.CommEvent = 2 then
  begin
    xtemp := msComm1.Input;
    SetLength(xScr,i);

    xScr := xtemp;

   for j:=0 to i-1 do
      xRecData := xRecData +char(xScr[j]);

   lstDisplay.Items.Add(FormatDateTime('hh:mm:ss', Now)
     +': ' +xRecData);
   lstDisplay.Items.Add('');
  end;
end;