委托和匿名委托

 public delegate void del();
            del d = Func;
            d.Invoke();
 public static void Func()
        {
            Console.WriteLine("i am delegate");
        }


 //无返回值
            Action<string> a1 = delegate(string a) { Console.WriteLine("I am action :{0}", a); };
            Action<string> a2 = (a => { Console.WriteLine("I am action :{0}",a); });
            a1.Invoke("");
            
           
            //有返回值
            Func<string> f = () => { return ""; };
            Func<string, string> f1 = a => { return a; };

            string re = f.Invoke();
            string re1 = f1.Invoke("");

            //返回bool
            Predicate<int> pr = a =>
            {
                if (a % 2 == 0)
                { return true; }
                else
                { return false; }
            };