我使用C++ Builder 6.0调用Win32 API实现的。
首先开一个线程。
void __fastcall TForm1::FormCreate(TObject *Sender)
{
ReadComm =new TRead232(true);
ReadComm->FreeOnTerminate = true;
}
通过一个按钮实现打开/关闭串口
void __fastcall TForm1::Button1Click(TObject *Sender)
{
if(Button1->Caption == "打开通讯端口") //按钮名称是"打开通讯端口"？
{
char *ComNo;
DCB dcb;
String Temp;
Temp = "COM"+IntToStr(rdCom->ItemIndex+1);
// TRadioGroup *rdCom; 定义要选择的串口
ComNo = Temp.c_str();
hComm =CreateFile(ComNo,GENERIC_READ|GENERIC_WRITE,
0,NULL,OPEN_EXISTING,0,0);
if(hComm == INVALID_HANDLE_VALUE)
{
MessageBox(0,"打开串口失败!!","Set Error",MB_OK);
return;
}
GetCommState(hComm,&dcb);
dcb.BaudRate = CBR_9600;
dcb.ByteSize = 8;
dcb.Parity = NOPARITY;
dcb.StopBits = ONESTOPBIT;
if(!SetCommState(hComm,&dcb))
{
MessageBox(0,"打通讯端口设置错误!!","Set Error",MB_OK);
CloseHandle(hComm);
return;
}
Timer1->Enabled = True;
Button1->Caption = "关闭串口";
Shape1->Brush->Color = clRed;
//启动接收线程
ReadComm->Resume();
}
else
{
Button1->Caption = "打开通讯端口";
CloseHandle(hComm);
Shape1->Brush->Color = clBlack;
Timer1->Enabled = False;
ReadComm->Terminate();
}
}
接收由线程TRead232完成
void __fastcall TRead232::Execute()
{
SetName();
//---- Place thread code here ----
if(!Terminated) Synchronize(ReadData);
}
//---------------------------------------------------------------------------
void __fastcall TRead232::ReadData()
{
Form1->Caption = "Updated in a thread";
String Temp;
char inbuff[1024];
DWORD nBytesRead,dwEvent,dwError;
COMSTAT cs;
if(hComm == INVALID_HANDLE_VALUE)
{
MessageBox(0,"串口失败!!","Set Error",MB_OK);
return;
}
ClearCommError(hComm,&dwError,&cs);
Form1->Edit1->Text = cs.cbInQue;
if(cs.cbInQue > sizeof(inbuff))
{
PurgeComm(hComm,PURGE_RXCLEAR);
return;
}
ReadFile(hComm,inbuff,cs.cbInQue,&nBytesRead,NULL);
inbuff[cs.cbInQue]='\0';
Form1->Memo1->Text =Form1->Memo1->Text+inbuff;
}
发送是定时器TIMER1触发，定时发送的。
void __fastcall TForm1::Timer1Timer(TObject *Sender)
{
char SendData[20];
byte ch;
int i;
unsigned long lrc,BS;
if (hComm==0) return;
SendData[0] = 0x41;
SendData[1] = 0x03;
SendData[2] = 0x00;
SendData[3] = 0x01;
SendData[4] = 0x00;
SendData[5] = 0x04;
SendData[6] = 0x1b;
SendData[7] = 0x09;
SendData[8] = '\0';
// BS = 8; // StrLen(SendData);
for(i=0;i<=7;i++)
{
ch = SendData;
WriteFile(hComm,&ch,1,&lrc,NULL);
}
}
原来想一起发的，发现不成功，还是一个一个发就没有问题了。 |
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