委托的例子，from C# advanced program

    class BubbleSorter
    {
        static public void Sort<T>(IList<T> sortArray, Func<T, T, bool> comparison)
        {
            bool swapped = true;
            do
            {
                swapped = false;
                for (int i = 0; i < sortArray.Count - 1; i++)
                {
                    if (comparison(sortArray[i+1], sortArray[i]))
                    {
                        T temp = sortArray[i];
                        sortArray[i] = sortArray[i + 1];
                        sortArray[i + 1] = temp;
                        swapped = true;
                    }
                }
            } while (swapped);

       
        }
    }

    class Employee
    {
        public Employee(string name, decimal salary)
        {
            this.Name = name;
            this.Salary = salary;
        }

        public string Name { get; private set; }
        public decimal Salary { get; private set; }

        public override string ToString()
        {
            return string.Format("{0}, {1:C}", Name, Salary);
        }

        public static bool CompareSalary(Employee e1, Employee e2)
        {
            return e1.Salary < e2.Salary;
        }
    }

    class Program
    {
        static void Main()
        {
            Employee[] employees =
            {
                new Employee("Bugs Bunny", 20000),
                new Employee("Elmer Fudd", 10000),
                new Employee("Daffy Duck", 25000),
                new Employee("Wile Coyote", 1000000.38m),
                new Employee("Foghorn Leghorn", 23000),
                new Employee("RoadRunner", 50000)
            };

            BubbleSorter.Sort(employees, Employee.CompareSalary);

            foreach (var employee in employees)
            {
                Console.WriteLine(employee);
            }

        }
    }