Problem with Event,serial port win32 API

[Aanand]

Hi all

That I'm working on the serial port win32 api and I must, my liaison with asynchronous read character go once they are received on the serial port.

so I wrote this code.

C + + code:

  # include <windows.h> 
  # include <assert.h> 
  # include <stdlib.h> 
  # include <conio.h> 
  # include <stdio.h> 
  # include <vcl.h> 
  # pragma hdrstop 

  //------------------------------------------------ --------------------------- 

  # pragma argsused 
  int main (int argc, char * argv []) 
  ( 
          Overlapped over; 
          HANDLE hComm; 
          DWORD EventMask; 
          hComm = CreateFile ( "COM1", GENERIC_WRITE | GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL); 
          if (hComm == INVALID_HANDLE_VALUE) ( 
                  printf ( "Error opening port"); 
          Else () 
                  if (SetCommMask (hComm, EV_RXCHAR)) ( 
                          over. hEvent = CreateEvent ( 
                                  NULL, 
                                  TRUE, 
                                  FALSE, 
                                  NULL); 
                          over. Internal = 0; 
                          over. InternalHigh = 0; 
                          over. Offset = 0; 
                          over. OffsetHigh = 0; 
                          assert (over.a hEvent); 
                          while (true) ( 
                                  if (WaitCommEvent (hComm, & EventMask, & over)) ( 
                                          if (EventMask & EV_RXCHAR) ( 
                                                  printf ( "character received"); 
                                                  getch (); 
                                          ) 
                                  ) 
                                  else ( 
                                          printf ( "Error% d", GetLastError ()); 
                                          getch (); 
                                  ) 
                          ) 
                  Else () 
                          printf ( "error creation event% d", GetLastError ()); 
                  ) 
          ) Getch (); 
          return 0; 
  )

Outside I have a big problem, waitcommevent me always returns 0, so the error getlast I watch what I can and if I take it in my loop I have something like

Error 997 ERROR_IO_PENDING
Error 87 ERROR_INVALID_PARAMETER

So now it's been a good time am with the forums and but I can not find anything so I put my query here.

If you have an genius idea please let me know.

(in case I test the connection with hyperterminal no problem 2)

[Astro121]

You should perhaps re-structure overlapped between each call. when i tried out different program with little bit of same logic, I do not repeat the event, by against) ...

[Aanand]

I rebuilt my structure is no longer the event

[Astro121]

Just remember its handle to another variable ...

 # include <windows.h> 
  # include <assert.h> 
  # include <stdlib.h> 
  # include <conio.h> 
  # include <stdio.h> 

  //------------------------------------------------ --------------------------- 

  # pragma argsused 
  int main (int argc, char * argv []) 
  ( 
	  HANDLE hComm; 
	  hComm = CreateFile ( "COM1", GENERIC_WRITE | GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL); 
	  if (hComm == INVALID_HANDLE_VALUE) ( 
		  printf ( "Error opening port"); 
	  Else () 
		  if (SetCommMask (hComm, EV_RXCHAR)) ( 
			  HANDLE hEvent = CreateEvent ( 
			   NULL, 
			   TRUE, 
			   FALSE, 
			   NULL); 
			  while (true) ( 
				  DWORD EventMask; 
				  Overlapped over; 
				  over. hEvent = hEvent; 
				  over. Internal = 0; 
				  over. InternalHigh = 0; 
				  over. Offset = 0; 
				  over. OffsetHigh = 0; 
				  assert (over.a hEvent); 
				  if (WaitCommEvent (hComm, & EventMask, & over)) ( 
					  if (EventMask & EV_RXCHAR) ( 
						  printf ( "character received"); 
						  getch (); 
					  ) 
				  Else () 
					  printf ( "Error% d", GetLastError ()); 
					  getch (); 
				  ) 
			  ) 
		  Else () 
			  printf ( "error creation event% d", GetLastError ()); 
		  ) 
	  ) 
	  getch (); 
	  return 0; 
  )

But on the other hand, I think that this was not the source of the problem: The problem is apparently that WaitCommEvent () is supposed to return ERROR_IO_PENDING and that you must then do a WaitForSingleObject () on hEvent. ..

[Aanand]

I try solution 2

still nothing

Edit: I replace the FILE_FLAG_OVERLAPPED with 0 and now it goes, but after I'll have to know why> <(I must submit my project for my project) so someone will have an idea?