C#等待异步操作执行完的方式
代码实现:
namespace AsyncCallbackDemo1 { class Program { static void Main(string[] args) { //<参数,返回值> Func<int, int> mySum1 = SumNumbers; Func<int, int> mySum2 = SumNumbers; Func<int, int> mySum3 = SumNumbers; AsyncCallback callback = c => Console.WriteLine("線程ID:{0},回調函數執行:{1}", Thread.CurrentThread.ManagedThreadId, c.AsyncState); IAsyncResult result1 = mySum1.BeginInvoke(10000, callback, "第一個異步"); IAsyncResult result2 = mySum2.BeginInvoke(10000, callback, "第二個異步"); IAsyncResult result3 = mySum3.BeginInvoke(10000, callback, "第三個異步"); //异步等待方式1:使用EndInvoke int asyc1 = mySum1.EndInvoke(result1); Console.WriteLine("第一個異步已經執行完成,結果:{0}", asyc1); //异步等待方式2:使用AsyncWaitHandle.WaitOne,参数-1表示一直等待到执行完成 if (result2.AsyncWaitHandle.WaitOne(-1)) { Console.WriteLine("第二個異步已經執行完成"); } //异步等待方式3:使用IsCompleted判断 while (!result3.IsCompleted) { Console.WriteLine("第三個異步還在執行中...."); Thread.Sleep(300); } Console.WriteLine("第三個異步已經執行完成"); Console.ReadKey(); } public static int SumNumbers(int count) { int sum = 0; for (int i = 0; i < count; i++) { sum += i; } Thread.Sleep(3000);//3秒 return sum; } } }
执行截图: