LaunchDarkly sample .NET client-side application

We've built simple demo applications that demonstrate how the LaunchDarkly client-side .NET SDK works. There are two demos:

• Console app (DotNetConsoleApp): A .NET console application.
• MAUI app (MauiApp): A .NET MAUI application targeting Android and iOS.

Below, you'll find the build procedures. For more comprehensive instructions, you can visit your Quickstart page or the client-side .NET SDK reference guide.

These demos require .NET 8.0 or higher.

Console app

1. Set the value of the mobileKey variable in DotNetConsoleApp/Program.cs to your mobile key:

   const string mobileKey = "my-mobile-key";

   Alternatively, set the LAUNCHDARKLY_MOBILE_KEY environment variable:

   export LAUNCHDARKLY_MOBILE_KEY="my-mobile-key"

2. If there is an existing boolean feature flag in your LaunchDarkly project that you want to evaluate, set flagKey to the flag key:

   const string flagKey = "my-flag-key";

   Otherwise, sample-feature will be used by default.

3. On the command line, run:

   dotnet run --project DotNetConsoleApp

   You should receive the message:

   "The sample-feature feature flag evaluates to false."

The application will run continuously and react to the flag changes in LaunchDarkly.

MAUI app (Android & iOS)

The MAUI app demonstrates LaunchDarkly in a mobile context using .NET MAUI, targeting both Android and iOS from a single project.

1. Install the MAUI workload if you haven't already:

   dotnet workload install maui

2. Copy the example settings file and set your mobile key:

   cp MauiApp/Resources/Raw/appsettings.example.json MauiApp/Resources/Raw/appsettings.json

   Then edit MauiApp/Resources/Raw/appsettings.json and set your mobile key:

   {
     "MobileKey": "my-mobile-key",
     "FlagKey": "sample-feature"
   }

   The appsettings.json file is gitignored to prevent committing your key.

3. Build and run:

   • Android (deploy to a connected device or emulator):

     dotnet build MauiApp -f net8.0-android -t:Run

   • iOS (requires macOS with Xcode; deploy to a simulator):

     dotnet build MauiApp -f net8.0-ios -t:Run

The app displays the current value of the feature flag. The background color changes from dark (#373841) to green (#00844B) when the flag evaluates to true. The app reacts to flag changes in real time.