示例#1
0
        static void Main(string[] args)
        {
#if UseDelegate
            //创建多播委托
            multiDelegate  = MultiDelegate.Func1;
            multiDelegate += MultiDelegate.Func2;

            //调用委托,观察结果
            try
            {
                multiDelegate();
            }
            catch (Exception e)
            {
                Console.WriteLine(e);
            }

            Console.WriteLine("---------------------------分割线------------------------------");
            //手动迭代委托方法列表,可以处理抛出异常后委托链终止执行的问题
            //定义方法列表数组,使用GetInvocationList()
            //注意使用的是Delegate类,不是delegate关键字
            Delegate[] myDelegates = multiDelegate.GetInvocationList();
            foreach (var @delegate in myDelegates)
            {
                var delegateItem = (Action)@delegate;
                //分别调用委托
                try
                {
                    delegateItem();
                }
                catch (Exception e)
                {
                    Console.WriteLine(e);
                }
            }
#elif UseEvent
            //依次注册事件
            multiEvent += MultiDelegate.Func1;
            multiEvent += MultiDelegate.Func2;

            //调用事件,观察结果
            try
            {
                multiEvent();
            }
            catch (Exception e)
            {
                Console.WriteLine(e);
            }

            Console.WriteLine("---------------------------分割线------------------------------");
            //手动迭代委托方法列表,可以处理抛出异常后委托链终止执行的问题
            //定义方法列表数组,使用GetInvocationList()
            //注意使用的是Delegate类,不是delegate关键字

            Delegate[] myDelegates = multiEvent.GetInvocationList();
            foreach (var @delegate in myDelegates)
            {
                var delegateItem = @delegate as Action;
                try
                {
                    delegateItem();
                }
                catch (Exception e)
                {
                    Console.WriteLine(e);
                }
            }
#endif
            Console.WriteLine("---------------------------分割线------------------------------");
            getResultDelegate  = MultiDelegate.GetOne;
            getResultDelegate += MultiDelegate.GetTwo;

            Console.WriteLine("直接调用委托返回的一般是最后一个方法的返回值:" + getResultDelegate());

            //手动迭代委托方法列表,可以获取并处理每个委托的返回值
            //定义方法列表数组,使用GetInvocationList()
            //注意使用的是Delegate类,不是delegate关键字
            int        sum             = 0;
            Delegate[] resultDelegates = getResultDelegate.GetInvocationList();
            foreach (var @delegate in resultDelegates)
            {
                var delegateItem = @delegate as GetResult;
                sum += delegateItem();
                Console.WriteLine("获取单个委托的返回值:" + delegateItem());
            }
            Console.WriteLine("多个委托的返回值总和:" + sum);
        }