Question

我是TPL的新手，所以只是通过一些关于相同的教程， http://msdn.microsoft.com/en-us/library/dd537609(v=vs.110).aspx

在上面链接我正在尝试使用此代码



 var displayData = Task.Factory.StartNew(() => { 
                                         Random rnd = new Random(); 
                                         int[] values = new int[100];
                                         for (int ctr = 0; ctr <= values.GetUpperBound(0); ctr++)
                                            values[ctr] = rnd.Next();

                                         return values;
                                      } ).  
                ContinueWith((x) => {
                                int n = x.Result.Length;
                                long sum = 0;
                                double mean;

                                for (int ctr = 0; ctr <= x.Result.GetUpperBound(0); ctr++)
                                   sum += x.Result[ctr];

                                mean = sum / (double) n;
                                return Tuple.Create(n, sum, mean);
                             } ). 
                ContinueWith((x) => {
                                return String.Format("N={0:N0}, Total = {1:N0}, Mean = {2:N2}",
                                                     x.Result.Item1, x.Result.Item2, 
                                                     x.Result.Item3);
                             } );

我正在使用我的代码替换上面的代码

 var taskList = Task.Factory.StartNew(() => {
                var newRandom = new Random();
                var intArray = new int[100];
                Console.WriteLine("Begining  of First  Iteration");
                Parallel.For(0, intArray.GetUpperBound(0) - 1, i =>
                {
                    intArray[i] = newRandom.Next();
                    Console.WriteLine(i);
                });
                Console.WriteLine("End of First Iteration");

            }).ContinueWith((x) => {
                Console.WriteLine("Beginning of Second  Iteration");
                int n = x.Result.Length;
                long sum = 0;
                double mean;

                for (int ctr = 0; ctr <= x.Result.GetUpperBound(0); ctr++)
                    sum += x.Result[ctr];

                mean = sum / (double)n;
                Console.WriteLine("End of  Second Iteration");
                return Tuple.Create(n, sum, mean);
                });

我收到错误::

 var taskList = Task.Factory.StartNew(() => {
                var newRandom = new Random();
                var intArray = new int[100];
                Console.WriteLine("Begining  of First  Iteration");
                Parallel.For(0, intArray.GetUpperBound(0) - 1, i =>
                {
                    intArray[i] = newRandom.Next();
                    Console.WriteLine(i);
                });
                Console.WriteLine("End of First Iteration");

            }).ContinueWith((x) => {
                Console.WriteLine("Beginning of Second  Iteration");
                int n = x.Result.Length;
                long sum = 0;
                double mean;

                for (int ctr = 0; ctr <= x.Result.GetUpperBound(0); ctr++)
                    sum += x.Result[ctr];

                mean = sum / (double)n;
                Console.WriteLine("End of  Second Iteration");
                return Tuple.Create(n, sum, mean);
                });

找不到＆＃34;结果＆＃34;

我做错了什么？

Answer 1

Task类没有Result属性，Task<T>属性。

问题是，StartNew中的代理人没有返回值，因此它解析为返回Task而不是Task<T>。

尝试添加此内容：

...
Console.WriteLine("End of First Iteration");
return intArray;

并行任务，在使用ContinueWith时，第一个操作的结果没有找到

1 个答案: