Question

I’m trying to create an abstract class, defining an abstract method, that is to be derived from other classes that implements some specific behavior in the abstract method. I want the abstract class to contain some kind of state information that represents however the implementation in the derived classes exited without errors, but I want to implement all state handling in AbstractClass and not in the deriving classes. I want to make the deriving classes totally unaware of the functionality in AbstractClass. Below is an example. I made comments in the code to describe what I’m trying to achieve.

public abstract class AbstractClass
    {
        public void Start()
        {
            ThreadStart ts = new ThreadStart(PerformWork);
            Thread t = new Thread(ts);
            t.Start();
            Thread.Sleep(2000);

            // Dependent on if ReportWork exited without expcetions
            // I want to call ReportSuccess or ReportFailure from this method.
            // However, I dont want to implement any reporting functionallity (or
            // as little as possible)
            // into the deriving classes PerformWork() method. Simply put
            // I want the deriving classes to be totally unaware of the reporting. 

        }

        public void ReportSuccess()
        {
            Console.WriteLine("Success!");
        }

        public void ReportFailure()
        {
            Console.WriteLine("Failure!");
        }
        public abstract void PerformWork();
    }

A class deriving from AbstractClass:

class ConcreteImplementationClass:AbstractClass
    {
        public override void PerformWork()
        {
            // Implements some functionality
            // without knowing anything about
            // whats going on in AbstractClass.           
        }
    }

Do anyone have any advice for how I could achieve this functionality, or how I could create something similar?

Answer 1

If I understand this correctly you want to call ReportSuccess() if the PerformWork() is successfully and ReportFailure() if it fails?

Why not change

public abstract void PerformWork();

to

public void Start()
{
    bool result = false;

    // This will enable Perform work to operate in its own thread
    Action threadAction = new Action(() =>
        {
            result = PerformWork();
        });

    ThreadStart ts = new ThreadStart(threadAction);
    Thread t = new Thread(ts);
    t.Start();
    Thread.Sleep(2000);

    // Dependent on if ReportWork exited without expcetions
    // I want to call ReportSuccess or ReportFailure from this method.
    // However, I dont want to implement any reporting functionallity (or
    // as little as possible)
    // into the deriving classes PerformWork() method. Simply put
    // I want the deriving classes to be totally unaware of the reporting. 

    if(result)
    {
        ReportSuccess();
    }
    else
    {
        ReportFailure();
    }
}