Question

I’m working on some existing code. After a few hours, I’ve boiled this problem down to a method picker class. I find this class to be difficult to follow. Is it possible to achieve this type of method picking functionality in a simple way?

public class MethodPicker
    {
        private delegate string SomeFunc(MethodPicker item);

        static readonly Dictionary<string, SomeFunc> test = new Dictionary<string, SomeFunc>();

        static MethodPicker()
        {
            test.Add("key1", Func1);
            test.Add("key2", Func2);
            test.Add("key3", Func3);
        }

        public string RunTest(string Name)
        {
            string somestring = test[Name].Invoke(this);
            return somestring;
        }

        public static string Func1(MethodPicker entity)
        {
            return "func1 runs";
        }

        public static string Func2(MethodPicker entity)
        {
            return "func2 runs";
        }

        public static string Func3(MethodPicker entity)
        {
            return "func3 runs";
        }
    }

Answer 1

Well this would be a simpler solution..

public class MethodPicker
    {
        public string RunTest(string Name)
        {
           string somestring;
           if (Name.equals("key1") 
              return Func1(this);
           else if(Name.equals("key2") 
               return Func2(this);
           else if (Name.equals("key3") 
               return Func3(this);
           else 
              throw new Exception(name + " not found.. ");
        }

        public static string Func1(MethodPicker entity)
        {
            return "func1 runs";
        }

        public static string Func2(MethodPicker entity)
        {
            return "func2 runs";
        }

        public static string Func3(MethodPicker entity)
        {
            return "func3 runs";
        }
    }

It also highlights what is a potential problem in the dictionary solution as you have no proper error handling if the key/name does not exist in the dictionary. In your solution it would cause a NullPointerException here:

string somestring = test[Name].Invoke(this);

test[Name] would be return null…