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

        if (env.IsEnvironment("Development"))
        {
            // This will push telemetry data through Application Insights pipeline faster, allowing you to view results immediately.
            builder.AddApplicationInsightsSettings(developerMode: true);
        }

        builder.AddEnvironmentVariables();
        Configuration = builder.Build();
    }

    public IConfigurationRoot Configuration { get; }

    // This method gets called by the runtime. Use this method to add services to the container
    public void ConfigureServices(IServiceCollection services)
    {
        // Add framework services.
        services.AddApplicationInsightsTelemetry(Configuration);

        services.AddMvc();
    }

    // This method gets called by the runtime. Use this method to configure the HTTP request pipeline
    public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
    {
        loggerFactory.AddConsole(Configuration.GetSection("Logging"));
        loggerFactory.AddDebug();

        app.UseApplicationInsightsRequestTelemetry();

        app.UseApplicationInsightsExceptionTelemetry();

        app.UseMvc();
    }
}

public class MyClass 
{
    private IConfiguration configuration;
    public MyClass(IConfiguration configuration)
    {
        ConnectionString = new configuration.GetValue<string>("ConnectionString");
    }
}

        public void ConfigureServices(IServiceCollection services)
        {
            services.AddTransient<MyClass>();
            services.AddControllers();
        }

public class MyController : ControllerBase
{
    private MyClass _myClass;

    public MyController(MyClass myClass)
    {
        _myClass = myClass;
    }
}

public static class MyAppData
{
    public static IConfiguration Configuration;
}


public Startup(IConfiguration configuration)
{
    Configuration = configuration;
    MyAppData.Configuration = configuration;
}

    private static string AppKey = ConfigurationManager.AppSettings["AppKey"];