Delegate中的异步调用

 1namespace Bingosoft.Training2007.CSharp

 2{

 3    delegate int Sum(int num1,int num2);

 4    /**//// <summary>

 5    /// 使用Delegate的BeginInvoke方法完成一个函数的异步调用过程。

 6     /// </summary>

 7    class Question6

 8    {

 9        /**//// <summary>

10        /// 求两个int型数的和(仅供演示)

11        /// </summary>

12        /// <param name="num1"></param>

13        /// <param name="num2"></param>

14        /// <returns></returns>

15        public static int GetSum(int num1, int num2)

16        {

17            Thread.Sleep(1000);

18            return num1 + num2;            

19        } 

20

21        /**//// <summary>

22        /// 用EndInvoke等待异步调用

23         /// </summary>

24        public static void TestAsyn1()

25        {

26            Sum sum = new Sum(GetSum);

27            IAsyncResult result = sum.BeginInvoke(10, 20,null,null);

28            Console.WriteLine("计算中");

29            int returnVal = sum.EndInvoke(result);

30            Console.WriteLine(returnVal);

31        } 

32

33        /**//// <summary>

34        /// 用WaitHandle等待异步调用

35         /// </summary>

36        public static void TestAsyn2()

37        {

38            Sum sum = new Sum(GetSum);

39            IAsyncResult result = sum.BeginInvoke(10, 20, null, null);

40            result.AsyncWaitHandle.WaitOne();

41            Console.WriteLine("计算完毕：");

42            int returnVal = sum.EndInvoke(result);

43            Console.WriteLine(returnVal);

44        } 

45

46        /**//// <summary>

47        /// 轮训查询等待异步调用

48         /// </summary>

49        public static void TestAsyn3()

50        {

51            Sum sum = new Sum(GetSum);

52            IAsyncResult result = sum.BeginInvoke(10, 20, null, null);

53            while (!result.IsCompleted)

54            {

55                Console.WriteLine("计算中");

56            }

57            int returnVal = sum.EndInvoke(result);

58            Console.WriteLine(returnVal);

59        } 

60

61        /**//// <summary>

62        /// 异步调用完成后，执行回调

63         /// </summary>

64        public static void TestAsyn4()

65        {

66            Sum sum = new Sum(GetSum);

67            IAsyncResult result = sum.BeginInvoke(10, 20, new AsyncCallback(Question6.CallBackAsyn), sum);

68            Console.WriteLine("计算中");

69        } 

70

71        /**//// <summary>

72        /// 回调函数

73         /// </summary>

74        /// <param name="ar"></param>

75        public static void CallBackAsyn(IAsyncResult ar)

76        {

77            Sum sum = (Sum)ar.AsyncState;

78            int returnVal = sum.EndInvoke(ar);

79            MessageBox.Show(returnVal.ToString(), "计算结果:", MessageBoxButtons.OK, MessageBoxIcon.Information);

80        }

81    }

82}

83 

84

85//测试Question6

86Question6.TestAsyn1();

87Question6.TestAsyn2();

88Question6.TestAsyn3();

89Question6.TestAsyn4();

90Console.WriteLine("Press any Key to Continue");

91Console.ReadLine();

92