MSFS MSFS2020 SimConnect in Winforms && Wpf WORKING, but some help needed. CODE EXAMPLES INCLUDED

[jpdise]

I have a partially working CSharp wrapper that seems to be communicating with MSFS2020 via SimConnect failry well. I am however, running into some issues with a few of the SimVars and was hoping someone could help me out. Specifically, I am unable to get the following values from SimConnect that I would like to:

[The current % setting of the throttle handle]
I cannot figure out what is the proper value for the SimVar name. I am currently using "GENERAL ENG THROTTLE LEVER POSITION:index", but that doesn't appear to be working. Is the ":index" meant to represent something like "index of the engine)"? So, in a twin engine plane I would do "GENERAL ENG THROTTLE LEVER POSITION:1" for the second engine? I'm able to parse the "FLAPS HANDLE PERCENT" SimVar, so if I can just get the throttle data to come across, I should be able to handle it.

[ATC information, such as ATC ID, ATC TYPE etc]
I have had no luck capturing ANY string information. I've tried every variation of STRING8, STRING32, STRING54, STRING128, STRING256, STRINGV to get the proper data on string types. I am also not sure what should be passed as the unit when getting strings. I've seen "null" passed elsewhere for unit type on string values, but still have had no success. For strings, I need help ensuring that I'm using the proper SimVar names, as well as DataTypes, and also that my data struct has been properly defined.

I have built a polling request system like you see present in the SDK samples. I am going to include some code snippets so you may be able to help me diagnose the issue. Long story short, I need to make sure that I'm registering my calls via SimConnect.AddToDataDefinition() correctly and that my struct has the fields defined properly, because that is likely where the issue is.


Here is my return data STRUCT that should contain the requested data from SimConnect:

[StructLayout(LayoutKind.Sequential, Pack = 1)]
public struct ATCInfo
{
    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 64)]
    public string Type_Name;
    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 8)]
    public string Tail_Number;
}

Here are the calls to register my request:

                                  *this is correct       *??       *??      *??
simConnector.AddToDataDefinition(DEFINITIONS.ATCInfo, "ATC TYPE", null, SIMCONNECT_DATATYPE.STRING64, 0, SimConnect.SIMCONNECT_UNUSED);
simConnector.AddToDataDefinition(DEFINITIONS.ATCInfo, "ATC FLIGHT NUMBER", null, SIMCONNECT_DATATYPE.STRING8, 0, SimConnect.SIMCONNECT_UNUSED);
simConnector.RegisterDataDefineStruct<ATCInfo>(DEFINITIONS.ATCInfo);

I am getting exceptions number 7 & 3 from the SimConnect library when trying to get these string values.

Can anyone provide some direction?


P.S. I'll be happy to post my working WinForms & WPF implementation if anyone would like to see it.

 

[jpdise]

@rupture I see you are working with managed library as well. Any insight here?

 

[jpdise]

@David McClanahan it appears that you are working with the managed library as well. I haven't tried setting any variables yet, but are you able to read string type variables from SimConnect? Are you GETTING the throttle variable? If so, are you using the event system, or polling for it?

 

[WarpD]

The index is engine number... and there is no engine number 0. It is a 1-based index for all of the SimConnect variables that have an index value.

At what point in your code are you getting the exceptions? Also, exceptions usually have a name associated with them, not strictly a number. The only thing I see different between your code and example(s) in the SDK are that they have (uint) in front of the DEFINITIONS.ATCInfo in the AddToDataDefinition statement.

 

[jpdise]

@WarpD Thanks for the update on the Throttle info. The 1-based starting index was my mixup. Cheers!

 

[ZenMusic]

I have a partially working CSharp wrapper that seems to be communicating with MSFS2020 via SimConnect failry well.

P.S. I'll be happy to post my working WinForms & WPF implementation if anyone would like to see it.

I'd really appreciate seeing the code, I have the beginning of an C# app working to collect in one display somethings I find useful, throttle, ground speed (for taxi), parking brake state, AutoThrust state etc. I intended to add a governor (speed control) for taxiing .. and co-pilot call outs for speed and V1 and any reminders I want (maybe gear up, flaps up .. etc.) Just doing it for myself to learn but I haven't set any states yet

 

[rupture]

I'm currently not getting any sim vars that are string types. I may have to mess with that to see.

 

[jpdise]

@David McClanahan Here is the code along with a compiled library. It is a very simple wrapper. Here is simple Winforms implementation. Just need to pass the window handle on constructor and subscribe to the AircraftStatusUpdated event. Calling Start() method begins the polling. You can set a couple parameters. SetRefreshInterval(int miliseconds) will set the update period. SetRequestVerbosity(typeof(RequestVerbosity)) will change the quantity of data returned in the event, but it defaults to the highest level on initialization.

using MSFSClient;

client = new MSFSClient.MSFSClient(this.Handle);
client.AircraftStatusUpdated += Client_AircraftStatusUpdated;
client.Start();


private void Client_AircraftStatusUpdated(AircraftStatus status)
{
    UpdateAircraftStatus(status); //Do whatever you want with the AircraftStatus object here. It contains the real-time info from MSFS
}

It is also imperative that you have the following code in your Form (this will capture the windows messages for SimConnect):

protected override void WndProc(ref Message m)
{
    base.WndProc(ref m);
     if (m.Msg == 0x0402)
     {
         client.ReceiveMessage();
     }
}

 

[jpdise]

As an update, I am no longer getting the exceptions and have registered a request properly for the string variables. It is returning data now, but when I parse it I am ending up with sometimes readable characters and sometimes garbage. I'm fairly certain it has to do with the defined length of the string type on my data STRUCT.

 

[jpdise]

It appears that I have the strings working relatively correctly now. The only one that is still a little suspect is the variable length string. It appears that not specifying a constant length string field on the DATA struct causes some issue. I'm using a length of 64 to get the "TITLE" SimVar and I have yet to see any negative side effects...

P.S. I should also add that I've put the variable length string as the last field in my struct. That way a pre-defined string length should be truncated at worst (so far haven't run into any index out of bounds issues).

 

[jpdise]

Here is a snapshot of the data I'm able to get updates on at the moment. This is not exhaustive by any stretch of the imagination. Just a sample of some things I wanted to see.

 

[ZenMusic]

thanks, that's great; I'll get back to you when I've run it ..

 

[ZenMusic]

do you have some insight into the Waypoint array? I can see that they are indexed but I can't get any descriptive text about them.

Is there a variable or function to give me current distance from the destination?

 

[jpdise]

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[maugiroe]

@jpdise I have the same issue with the string. I would like to get the title, how finally did you manage to do that ? I download your example but the atc string part seems commented. Thanks

 

[jpdise]

Hi @maugiroe, here is a sample request for a string. The IMPORTANT part is that you must define your string length properly in your data struct. My newest iteration of the SimConnect Wrapper has done away with multi-variable data structures in favor or single entity requests. This way I don't run into string length errors when parsing the returned data structures. (If one of the casts fails in the Data Struct, then the rest of the struct doesn't get parsed). So, here is an example of how I register a string call for the "TITLE" SimVar:

 public void RegisterRequest(DataRequest request)
        {
            if(!Requests.Any((item) => item.RequestName == request.RequestName))
            {
                try
                {
                    request.DefinitionID = (RequestDefinition)GetRequestID();
                    _connector.AddToDataDefinition(request.DefinitionID, request.RequestName, null, request.DataType, 0f, (uint)0);
                    
                    switch (request.DataType)
                    {
                        case SIMCONNECT_DATATYPE.STRING64:
                            _connector.RegisterDataDefineStruct<StringVal64>(request.DefinitionID); //To properly parse the string it is IMPERATIVE that you use the proper struct type as your generic here
                            break;

                        default:
                            _connector.RegisterDataDefineStruct<double>(request.DefinitionID);
                            break;
                    }
                    Requests.Add(request);
                }
                catch(Exception excep)
                {
                    Console.WriteLine(excep.Message);
                }
            }
        }

public static DataRequest AircraftTitle
        {
            get
            {
                return new DataRequest()
                {
                    RequestName = SimvarNames.AircraftModelName, //This is a static string equal to "TITLE"
                    DataType = Microsoft.FlightSimulator.SimConnect.SIMCONNECT_DATATYPE.STRING64,
                    UnitLabel = null,
                    Value = string.Empty
                };
            }
        }

struct StringVal64 {[MarshalAs(UnmanagedType.ByValTStr, SizeConst = 64)] public string Value; }

The BIG change to my approach was allowing my RequestHandler to programmatically assign and manage the RequestDefinitionID as opposed to statically defining them.
Feel free to reach out with any questions.
-jpdise

 

[maugiroe]

Thank you very much @jpside, i try that as soon as possible

 

[maugiroe]

It works, thanks

 

[jpdise]

@maugiroe my pleasure!

 

[maugiroe]

@jpdise Hi
I wonder if you found a simvar who tell you on witch icao the plane is ? Currently i calculate the distance between the plane and the lat lon airport. I’m pretty sure there is another way.