Question

I have generic Result<T> generic class which I use often in methods to return result like this

public Result<User> ValidateUser(string email, string password)

There is ILoggingService interface in Result class for logging service injection but I do not find a way to inject actual implementation.

I tried to execute the code below but TestLoggingService intance is not injected into LoggingService property. It always return null. Any ideas how to solve it?

 using (var kernel = new StandardKernel())
            {               
                kernel.Bind<ILoggingService>().To<TestLoggingService>();
                var resultClass = new ResultClass();
                var exception = new Exception("Test exception");
                var testResult = new Result<ResultClass>(exception, "Testing exception", true);                
            }  


      public class Result<T>
        {

           [Inject]
           public ILoggingService LoggingService{ private get; set; } //Always get null


            protected T result = default(T);
            //Code skipped




            private void WriteToLog(string messageToLog, object resultToLog, Exception exceptionToLog)
            {

                LoggingService.Log(....); //Exception here, reference is null



        }

Answer 1

You are creating the instance manually using new. Ninject will only inject objects created by kernel.Get(). Furthermore it seems you try to inject something into a DTO which is not recommended. Better do the the logging in the class that created the result:

public class MyService
{
    public MyService(ILoggingService loggingService) { ... }

    public Result<T> CalculateResult<T>() 
    {
        Result<T> result = ...
        _loggingService.Log( ... );
        return result;
    }
}