ASP.NET Core—access Configuration from static class

Question

I want a simple static class that accesses the Configuration object. All the config info is already read in from the appsettings.json file in the Startup class. I just need an e

Answer 1

After much research, this works (in ASPNetCore 2.2) for accessing the appsettings.json config from a static class but for some reason appsettings.development.json no longer loads properly but it might be something else in my project messing that up. The reloadOnChange does work. As a bonus it also has IHostingEnvironment and IHttpContextAccessor. While this works, I have recently decided to switch back to a more DI approach to follow the paradigm shift as others have mentioned.

So here is one of many ways to access some DI stuff (including the configuration) in a static class:

AppServicesHelper.cs:

public static class AppServicesHelper
{
        static IServiceProvider services = null;

        /// 

        /// Provides static access to the framework's services provider
        /// 
        public static IServiceProvider Services
        {
            get { return services; }
            set
            {
                if (services != null)
                {
                    throw new Exception("Can't set once a value has already been set.");
                }
                services = value;
            }
        }

        /// 

        /// Provides static access to the current HttpContext
        /// 
        public static HttpContext HttpContext_Current
        {
            get
            {
                IHttpContextAccessor httpContextAccessor = services.GetService(typeof(IHttpContextAccessor)) as IHttpContextAccessor;
                return httpContextAccessor?.HttpContext;
            }
        }

        public static IHostingEnvironment HostingEnvironment
        {
            get
            {
                return services.GetService(typeof(IHostingEnvironment)) as IHostingEnvironment;
            }
        }

        /// 

        /// Configuration settings from appsetting.json.
        /// 
        public static MyAppSettings Config
        {
            get
            {
                //This works to get file changes.
                var s = services.GetService(typeof(IOptionsMonitor)) as IOptionsMonitor;
                MyAppSettings config = s.CurrentValue;

                return config;
            }
        }
    }
}

Startup.cs:

public Startup(IHostingEnvironment env)
{
            var builder = new ConfigurationBuilder()
                .SetBasePath(env.ContentRootPath)
                .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
                .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true, reloadOnChange: true)
                .AddEnvironmentVariables();
            Configuration = builder.Build();
 }

 public void ConfigureServices(IServiceCollection services)
 {
//...

        services.AddHttpContextAccessor();//For HttpContext.

        // Register the IOptions object
        services.Configure(Configuration.GetSection(nameof(MyAppSettings)));

        //Explicitly register the settings object by delegating to the IOptions object so that it can be accessed globally via AppServicesHelper.
        services.AddSingleton(resolver => resolver.GetRequiredService>().CurrentValue);
 }

public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
//...
   AppServicesHelper.Services = app.ApplicationServices;
//...
}

Controller:

public class MyController: Controller
{
   public MyController()
   {
   }

   public MyAppSettings Config => AppServicesHelper.Config;

   public async Task doSomething()
   {
            testModel tm = await myService.GetModel(Config.Setting_1);
            return View(tm);
   }
}

Another class library:

public static class MyLibraryClass
{
     public static string GetMySetting_ => AppServicesHelper.Config.Setting_1; 
     public static bool IsDev => AppServicesHelper.HostingEnvironment.IsDevelopment();
}

MyAppSettings.cs is any class that maps to a MyAppSettings section in appsettings.json:

public class MyAppSettings
{
    public string Setting_1 {get;set;}
}

appsettings.json:

{
  "Logging": {
    "LogLevel": {
      "Default": "Warning"
    }
  },
  "AllowedHosts": "*",
  "MyAppSettings": {
      "Setting_1": "something"
   }
 }