經網上高手推薦C++Builder與RS-232一書, 我將第三章Line_Event程式改編成如下, 但出現了幾個問題, 1. 原本傳送五個位元組, 但GetOverlappedResult函數抓到只有四個 2. timer裡的WaitCommEvent(hComm,&EvWait,&OverLap)在接收位元後,卻不觸發EV_RXCHAR的EVENT 請問各位高手是否有遇到類似問題    #include  #pragma hdrstop #include "Unit1.h" //--------------------------------------------------------------------------- #pragma package(smart_init) #pragma resource "*.dfm" TForm1 *Form1; HANDLE hComm; void __fastcall SetEvent(); TEvent *WEvent; OVERLAPPED OverLap; TWaitResult EE; //--------------------------------------------------------------------------- __fastcall TForm1::TForm1(TComponent* Owner) : TForm(Owner) { WEvent =new TEvent(NULL,True,False,"") ; OverLap.hEvent = (HANDLE) WEvent->Handle; } //--------------------------------------------------------------------------- void __fastcall TForm1::Button1Click(TObject *Sender) { char *ComNo; DCB dcb; hComm = CreateFile("COM1",GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, FILE_FLAG_OVERLAPPED, 0); if (hComm == INVALID_HANDLE_VALUE) // 如果COM 未開啟 { MessageBox(0, "開啟通訊埠錯誤!!","Comm Error",MB_OK); return; } //將dcb位址傳入，以取得通訊參數 GetCommState(hComm,&dcb); // 得知目前COM 的狀態 dcb.BaudRate = CBR_9600; // 設定鮑率為9600 dcb.ByteSize = 8; // 位元組為 8 bit dcb.Parity = NOPARITY; // Parity 為 None dcb.StopBits = ONESTOPBIT; // 1 個Stop bit //通訊埠設定 if (!SetCommState(hComm, &dcb)) { // 設定COM 的狀態 MessageBox (0, "通訊埠設定錯誤!!!","Set Error",MB_OK); CloseHandle(hComm); return; } SetEvent(); } //--------------------------------------------------------------------------- void __fastcall TForm1::Button2Click(TObject *Sender) { if (hComm!=INVALID_HANDLE_VALUE) CloseHandle(hComm); exit(EXIT_SUCCESS); } //--------------------------------------------------------------------------- void __fastcall TForm1::Timer1Timer(TObject *Sender) { unsigned long EvWait; if (hComm==INVALID_HANDLE_VALUE) return; //若未開啟通訊埠則跳出 //等待事件的發生 if (WaitCommEvent(hComm,&EvWait,&OverLap)) { //先檢查Event EE=WEvent->WaitFor(10); if (EE!=wrSignaled ) return ;//若未觸發，則跳出 WEvent->ResetEvent();//清除事件 if (EvWait & EV_RXCHAR)//檢查readbuf是否接收的字元 { lblRX->Caption = IntToStr(StrToInt(lblRX->Caption) 1); if (spRX->Brush->Color==clRed) spRX->Brush->Color=clWhite; else spRX->Brush->Color=clRed; } } } //--------------------------------------------------------------------------- void __fastcall SetEvent() { long EvWait; if (hComm==0) return; EvWait=EV_RXCHAR; if (!SetCommMask(hComm,EvWait)) MessageBox (0, "設定錯誤!!","",MB_OK); Form1->Timer1->Enabled =true; } void __fastcall TForm1::SendClick(TObject *Sender) { DWORD dwrite,dRead; bool test; char ch[]="aaaaa"; test = HasOverlappedIoCompleted(&OverLap); WriteFile(hComm,&ch,6,&dwrite,&OverLap); GetOverlappedResult(hComm,&OverLap,&dRead,true); } //---------------------------------------------------------------------------