Injection into Console Application with the Simple Injector

You need to make Bootstrap.container available in Program.Main and then use it to create instances of classes instead of directly calling their constructors directly:

_testInjectedClass = Bootstrap.container.GetInstance<ITestInjectedClass>();

Of course you will need to expose it in Bootstrap for that to work:

class Bootstrap
{
    public static Container container;

    public static void Start()
    {
        container = new Container();

        // Register your types, for instance:
        container.Register<IUserRepository, UserRepository>(Lifestyle.Singleton);
        container.Register<ITestInjectedClass, TestInjectedClass>(Lifestyle.Singleton);
        //container.Register<IUserRepository, TestInjectedClass>(Lifestyle.Singleton);
        //container.Register<IUserContext, WinFormsUserContext>();
        container.Register<TestInjectedClass>();

        // Optionally verify the container.
        container.Verify();
    }
}

And call Bootstrap.Start from Program.Main:

static void Main(string[] args)
{ 
    Bootstrap.Start();

    _testInjectedClass = Bootstrap.container.GetInstance<ITestInjectedClass>();
    _testInjectedClass.UserRepoRun();

    Console.ReadLine();
}

The problem is because you are calling your Bootstrap code in Program class instance constructor.

So, actually when you start your program the execution environment, is calling entry point method Main. And your instance constructor is never executed.

Try changing your entry point method Main and 'Bootstrap' class code:

static void Main(string[] args)
{ 
     var container = new Container();
     Bootstrap.Start(container);
     _testInjectedClass = container.GetInstance<TestInjectedClass>();
     _testInjectedClass.UserRepoRun();

     Console.ReadLine();
}

class Bootstrap
{
    public static void Start(Container container)
    {
        // Register your types, for instance:
        container.Register<IUserRepository, UserRepository>(Lifestyle.Singleton);
        container.Register<ITestInjectedClass, TestInjectedClass>(Lifestyle.Singleton);
        container.Register<TestInjectedClass>();

        // Optionally verify the container.
        container.Verify();
    }
}