delphi 下API函数写串口

delphi 利用API函数写串口。 //建立串口句柄 CommHandle := CreateFile(PChar(ComboBox1.Text),GENERIC_WRITE or GENERIC_READ, 0,nil,OPEN_EXISTING,FILE_FLAG_OVERLAPPED or FILE_ATTRIBUTE_NORMAL,0); if CommHandle = INVALID_HANDLE_VALUE then begin CloseHandle(PostEvent); CloseHandle(ReadOs.hEvent); MessageBox(0,'串口打开失败!','Notice',MB_OK); StatusBar1.SimpleText := '串口打开失败'; Exit; end;