FSX SimConnect_CallDispatch in CALLBACK WndProc

[KWB]

C++, unmanaged code: Can I call SimConnect_CallDispatch in a WndProc callback?

My code is a .dll started in FSX under DLLs (dll.cfg). In DllMain / DLL_PROCESS_DLL_PROCESS_ATTACH I do attach my WndProc. Hence I do not need a own message loop.

This is why using (abusing?) this loop would be very convenient. But is this a good idea? Otherwise I would go ahead with TOWSIM's approach (see answers here) - message loop for SimConnect in own thread.

 

[KWB]

This approach seems to be impossible, moved on with the proposed own thread for SimConnect message loop. If someone has something similar running (one loop for WndProc and SimConnect message loop), please let me know.

 

[TOWSIM]

The example below works completely in an own thread. It even works in parallel to the window example I sent before. It is a must, if you contact SimConnect out of a DLL. Otherwise the DLL would block the program execution if you enter a loop in the DLL.

/*****************************************************************************
 COMMENT:   Opens a SimConnect for a specific activ thread or process

 GROUP:     ESP

 ENTRY:     void

 EXIT:      HRESULT should be S_OK if successful

*/


HRESULT ESPinterface::OpenESPconnection()
{
	HRESULT rval;
	EvHdl = CreateEvent(NULL,FALSE,FALSE,NULL);
	rval = SimConnect_Open(&SChdl,"ARIES",NULL,0,EvHdl,0);
	if(rval == S_OK)
		rep.Protocoll(BIT3,"SimConnect_Open successful");
	else
		rep.Protocoll(BIT3,"SimConnect_Open failed with %d",rval);

	ESPcon = SChdl;
	return(rval);
}

/*****************************************************************************
 COMMENT:   This thread keeps in contact with ESP an requests all necessary data

 GROUP:     ESP

 ENTRY:     ESPinterface*   a pointer to the existing class

 EXIT:      Always 0

*/


unsigned int WINAPI ESPthread(void* ESPclassPtr)
{
    HRESULT hr;
	double cycleTime,delta;

    DWORD nh,lpCnt = 0;
    ESP = (ESPinterface*)ESPclassPtr;
    ESP->ESPstatus |= ESP_THREAD_ACTIVE;
    hr = ESP->OpenESPconnection();
	ESPwx.SimCnct = ESP->ESPcon;						// share this handle with the WX class

    rep.Protocoll(BIT3,"In ESP thread");
    if(S_OK == hr)
    {
        rep.Protocoll(BIT3,"Connected to ESP");
        ESP->PreparerequestSets();						 // all type of requests like	SimConnect_AddToDataDefinition and	SimConnect_SubscribeToSystemEvent
        while(ESP->ESPstatus & ESP_THREAD_ACTIVE)
        {
            WaitForSingleObject(ESP->EvHdl,INFINITE);
            if(ESP->ESPstatus & ESP_THREAD_ACTIVE)
            {
                hr = SimConnect_RequestDataOnSimObjectType(ESP->ESPcon, REQUEST_1, RUN_DATA_DEF,0, SIMCONNECT_SIMOBJECT_TYPE_USER);	// runtime data
                if(!lpCnt)
                    rep.Protocoll(BIT3,"Received First ESP data");
                lpCnt++;
                if(!(lpCnt % 10))						// every 200 ms(  5 times per second)
                {
                    hr = SimConnect_RequestDataOnSimObjectType(ESP->ESPcon, REQUEST_2, SLOW_DATA_DEF, 0, SIMCONNECT_SIMOBJECT_TYPE_USER); // slow time data
                }
                if(!(lpCnt % 100) && !( rxMsgs & METAR_RECEIVED))   // every 2000 ms
                {																													// wx data
                    SimConnect_WeatherRequestObservationAtStation(ESP->ESPcon,REQUEST_3,"GLOB");
                }
                SimConnect_CallDispatch(ESP->ESPcon,(DispatchProc)&ESP->ESPdispatcher, NULL);
            }
            Sleep(ESP->ThreadCycleTimeMS);				// normally 20 ms  or whatever is convenient 
        }
 		  
    }
    ESP->CloseESPconnection();
	ESP->EvHdl = NULL;
	ESP->ESPcon = NULL;
    return 0;
}

Regards,
Mike

 

[KWB]

Yep, this is basically what I am doing right now. Thanks for all your support so far.