New Managed Class-Library started: CsSimConnect

[Bert Laverman]

In a follow-up to my earlier question, I have actually started building a new SimConnect library in C#. The code is available on GitHub under the Apache 2.0 license, which makes it free to use also for commercial purposes, but retains the copyright. Because this is 2021 I also claimed the Twitter handle @CsSimConnect and made a Facebook page for it, but more important is that "cssimconnect.org" is claimed and "blog.cssimconnect.org" sends you to "https://cssimconnect.wordpress.com" where I'll post development updates with examples of what I am trying to accomplish. The code compiles with the Prepar3D v4.5 and v5 SDK, as well as the v0.12.0 version of the MSFS SDK. It has three parts:

• "CsSimConnectInterOp" is a small C++ DLL project that links the static SimConnect library and exposes a DLL interface C# can call.
• "CsSimConnect" is the class-library itself.
• "CsSimConnectUI" is a small demo UI that is used to drive development; I decide for a feature to show in there, then implement what is needed to get it to work.

Current state:

• It connects to the simulator. Auto-connect (which will try regularly to connect or reconnect) is in the API but not there yet. There are "OnConnect" and "OnDisconnect" event handlers you can hook into.
• You can request and subscribe to the several System States.
• You can define ObjectData blocks containing integers, floats, and fixed-size strings and request the data once or subscribe to it.

Major refactorings needed:

• The actual calls to the SimConnect static library need an added layer of thread-safety, because the static library does not provide it. I currently have some locking in C# but intend to move those to the C++ layer.
• I use the "OnDisconnect" event in the library to simply clean out all request/event/definition/send ids, but this may need something a bit less drastic, maybe even auto-reregistration.

Data definition works using "Attributes", so you don't call "AddToDataDefinition" yourself, but provide a class looking like this:

public class AircraftData​

{​

[DataDefinition("ATC TYPE", Type = DataType.String256)]​

public string Type { get; set; }​

​

[DataDefinition("ATC MODEL", Type = DataType.String256)]​

public string Model { get; set; }​

​

[DataDefinition("ATC ID", Type = DataType.String256)]​

public string Id { get; set; }​

​

[DataDefinition("ATC AIRLINE", Type = DataType.String256)]​

public string Airline { get; set; }​

​

[DataDefinition("ATC FLIGHT NUMBER", Type = DataType.String256)]​

public string FlightNumber { get; set; }​

​

[DataDefinition("TITLE", Type = DataType.String256)]​

public string Title { get; set; }​

​

[DataDefinition("NUMBER OF ENGINES", Units = "Number", Type = DataType.Int32)]​

public int NumberOfEngines { get; set; }​

​

[DataDefinition("ENGINE TYPE", Units = "Number", Type = DataType.Int32)]​

public int EngineType { get; set; }​

}​

The library takes care of the rest. Using it looks like:

string aircraftTitle = DataManager.Instance.RequestData<AircraftData>().Get().Title;

Or even:

DataManager.Instance.RequestData<AircraftData>(ObjectDataPeriod.PerSecond, onlyWhenChanged: true)
.Subscribe((AircraftData data) => log.Info("[stream] Currently selected aircraft is '{0}'.", data.Title));

Note the data stream version will also get a "Subscribe()" (no parameters) and a "GetEnumerator()" that will return an "IEnumerator", so you can use "foreach" on it, and probably even LINQ-style streaming.

Feel free to use the GitHub Issues tab to suggest priorities, or make changes and send a PR.

Cheers,
Bert Laverman