App Center c++/c# SDK Interop

App Center will be retired in March 31, 2025. you can still see this project to learn ways of how to perform interop between dotnet projects and native applications (and viceversa in the other branch)

App Center Interop example for c++/c#(winforms).

App Center Build with this project

this steps will be called from the custom build scripts on App Center So you will need to set the following environment variables APPCENTER_APP_SECRET

• on this example the c++ project will contain the app center application secret
• build the project with the secret like this:

  meson builddir '-DAPPCENTER_APP_SECRET="<your secret>"'
  cd builddir
  meson compile

• this will generate a dll that needs to be copied to the c# project binary folder
• do the common steps for the c# project

From scratch guide

C# first Steps

• Create a new C# project.

  mkdir csharp
  cd csharp
  dotnet new winforms

• add AppCenter SDK to the project.

  dotnet add package Microsoft.AppCenter --version 4.4.0
  dotnet add package Microsoft.AppCenter.Analytics --version 4.4.0
  dotnet add package Microsoft.AppCenter.Crashes --version 4.4.0

• import AppCenter SDK on program.cs

  // Microsoft AppCenter SDK
  using Microsoft.AppCenter;
  using Microsoft.AppCenter.Analytics;
  using Microsoft.AppCenter.Crashes;

• init the SDK on program.cs like the example on this project

  static void Main()
  {
      // you can check more about App Center SDK at
      // https://docs.microsoft.com/en-us/appcenter/sdk/getting-started/wpf-winforms
      // do not store the app secret on source code
      // this is only for demo purposes
      System.Console.WriteLine("App Center Powered.");
      AppCenter.Start("{Your App Secret}", typeof(Analytics), typeof(Crashes));
  }    

C++ Steps

Basically, you need to create a new or use an existing C++ project so you can build a dll that will contain your code that get called from the C# project.

For demonstration purposes we will use meson/ninja to create a new C++ project and clang or msvc to compile it, but you can use your preferred toolchain (for example CMake) to build the dll.

in this example project it will show a dialog box for simplicity.

Loading c++ code from C#

after the dll is compiled, you can use it from the C# project.

• Copy the c++ dll(and all the required files) to the C# project binary folder.

  This step can be automated with a build script, as it is only needed when you deploy the release of the application.

• Add the following import to the C# code.

  // DllImport
  using System.Runtime.InteropServices;

• then add the function of the C++ DLL in the C# code like this:

  // define the DLL entry point from c++ dll (void dllEntry() from myApp.dll)
    [DllImport("myApp.dll", EntryPoint = "dllEntry")]
    public static extern void dllEntry();

Multiplatform Support

the SDK (C#) is only available for Windows, IOS and Android.

AppCenter Callbacks

you may need to call the SDK from the C++ code, for example when you want to send a crash report or log an event.

• in the C++ project setup a function that saves the C# callback function pointer into c++ so it can be called from the c++ code , you can check it on AppCenter.cpp.

  // the C function pointers
  void (*trackEventCallback)(const char *str) = nullptr;
  void (*trackEventExtraCallback)(const char *str, const char *data) = nullptr;
  // this functions will be called from another method in the c++ code
  void setTrackEventCallback(void (*callback)(const char *str)) {
      trackEventCallback = callback;
  }
  void setTrackEventCallback(void (*callback)(const char *str,
                                              const char *data)) {
      trackEventExtraCallback = callback;
  }

• once you have this functions you can call them directly or wrap them like this:

  void trackEvent(std::string event) {
        if (trackEventCallback) {
            trackEventCallback(event.c_str());
        } else {
            std::cerr << "Interop::AppCenter::trackEventCallback is nullptr\n";
        }
  }
  
  void trackEvent(std::string event, Properties properties) {
      if (trackEventExtraCallback) {
          trackEventExtraCallback(event.c_str(), toJson(properties).c_str());
      } else {
          std::cerr << "Interop::AppCenter::trackEventExtraCallback is nullptr\n";
      }
  }

• on AppCenter.hpp you can define them.
• finally define setupAppCenterCallbacks in the C++ project like this:

  extern "C"{
  // this will setup the callbacks needed by the C++ code
  // in order to call the AppCenter.trackEvent() function
  myAppAPI void setupAppCenterCallbacks(
    void (*trackEventCallback)(const char *str),
    void (*trackEventExtraCallback)(const char *str, const char *data)) {
        Interop::AppCenter::setTrackEventCallback(trackEventCallback);
        Interop::AppCenter::setTrackEventCallback(trackEventExtraCallback);
  }
  }

• on the C# project setup a class like the one on AppCenter.cs of this project.