Create a interface and inject with SimpleIoc

Question

I created a class AppConfig :

public class AppConfig
{
    private readonly IConfigurationRoot _configurationRoot;

    public AppConfig()
    {
        var builder = new ConfigurationBuilder()
            .SetBasePath(Package.Current.InstalledLocation.Path)
            .AddJsonFile("appsettings.json", optional: false);

        _configurationRoot = builder.Build();
    }

    private T GetSection<T>(string key) => _configurationRoot.GetSection(key).Get<T>();

    public Config Config => GetSection<Config>(nameof(Config));
}

And I use it like this in my ViewModels :

var config = new AppConfig();

But is there a better way to use this with Dependency Injection.

So that I can add it in the ViewModelLocator like other services?

public ViewModelLocator()
{
    SimpleIoc.Default.Register<ITestService, TestService>();

    SimpleIoc.Default.Register<MainViewModel>();
}

Or how would you do this in a UWP application with the MvvmLightLibsStd10?

Answer 1

Create in interface that abstracts the desired class.

public interface IAppConfig {
    Config Config { get; }
}

Derive the class from the interface

public class AppConfig : IAppConfig {
    //...omitted for brevity
}

and register the abstraction and implementation with the container

//...

SimpleIoc.Default.Register<IAppConfig, AppConfig>();

//...

Any thus class that needs use of the config can depend on it explicitly via constructor injection