串口问题

Question

我现在要将一个3万多字节的数据,每次发送256个字节到串口,怎么实现拆分数据啊

Answer 1

大致如此,没有测试:
procedure TForm1.Button1Click(Sender: TObject);
var
  FileBuf:TFileStream;
  DataBuf:TStream;
  i,k:integer;
begin
  FileBuf:=TFileStream.Create('d:\EXample.TXT',0);
  DataBuf:=TStream.Create;
  k:=FileBuf.Size DIV 256;
  For i:=0 to k do
    begin
    FileBuf.Seek(K*256,soFromBeginning);
    FileBuf.Read(DataBuf,256);
    Comm1.WriteCommData(Pchar(DataBuf),256);
    end;
 FileBuf.Free;
 DataBuf.Free;
end;

Answer 2

有一个笔误:
procedure TForm1.Button1Click(Sender: TObject);
var
  FileBuf:TFileStream;
  DataBuf:TStream;
  i,k:integer;
begin
  FileBuf:=TFileStream.Create('d:\EXample.TXT',0);
  DataBuf:=TStream.Create;
  k:=FileBuf.Size DIV 256;
  For i:=0 to k do
    begin
    FileBuf.Seek(i*256,soFromBeginning);
    FileBuf.Read(DataBuf,256);
    Comm1.WriteCommData(Pchar(DataBuf),256);
    end;
 FileBuf.Free;
 DataBuf.Free;
end;

Answer 3

对  chenylin(陈SIR)  的代码优化
var
  FileBuf:TFileStream;
  s:string;
  L:Integer;
begin
  FileBuf:=TFileStream.Create('d:\EXample.TXT',fmOpenRead or fmShareDenyNone);
  try
    SetLength(s,256);
    repeat
      L:=FileBuf.Read(s[1],256);
      if L>0 then
        //发送s，长度L
        ;
    until L=0;
  finally
    FileBuf.Free;
  end;