Barney.WaitForIt

A simple helper to perform async application initialization in .NET Core 2.0 or higher.

Usage

1. Install the Barney.WaitForIt NuGet package:

   Command line:

   dotnet add package Barney.WaitForIt

   Package manager console:

   Install-Package Barney.WaitForIt

2. Create a class (or several) that implements IAsyncInitializer. This class can depend on any registered service.

   public class MyAppInitializer : IAsyncInitializer
   {
       public MyAppInitializer(IFoo foo, IBar bar)
       {
           ...
       }
   
       public async Task InitializeAsync()
       {
           // Initialization code here
       }
   }

3. Register your initializer(s) in the Startup.ConfigureServices method:

       services.AddAsyncInitializer<MyAppInitializer>();

4. In the Program class, make the Main method async and change its code to initialize the host before running it:

   public static async Task Main(string[] args)
   {
       var host = new HostBuilder()
                       .ConfigureServices(configureServices)
                       .UseConsoleLifetime()
                       .Build();
       
       await host.WaitForItAsync();
       await host.StartAsync();
   }

(Note that you need to set the C# language version to 7.1 or higher in your project to enable the "async Main" feature.)

This will run each initializer, in the order in which they were registered.