C#怎么使用Task.ContinueWith組合任務(wù)

這篇文章主要講解了“C#怎么使用Task.ContinueWith組合任務(wù)”，文中的講解內(nèi)容簡(jiǎn)單清晰，易于學(xué)習(xí)與理解，下面請(qǐng)大家跟著小編的思路慢慢深入，一起來(lái)研究和學(xué)習(xí)“C#怎么使用Task.ContinueWith組合任務(wù)”吧！

代碼案例

簡(jiǎn)單Demo

代碼：

        public static void Main()
        {
            //創(chuàng)建一個(gè)任務(wù)
            Task<int> task = new Task<int>(() =>
            {
                int sum = 0;
                Console.WriteLine("使用Task異步執(zhí)行操作.");
                for (int i = 0; i <= 100; i++)
                {
                    sum += i;
                }
                return sum;
            });
            
            //啟動(dòng)任務(wù),并安排到當(dāng)前任務(wù)隊(duì)列線(xiàn)程中執(zhí)行任務(wù)(System.Threading.Tasks.TaskScheduler)
            task.Start();
            Console.WriteLine("主線(xiàn)程執(zhí)行其他程序.");
           
            //任務(wù)完成時(shí)執(zhí)行處理。
            Task cwt = task.ContinueWith(t =>
            {
                Console.WriteLine("任務(wù)完成後的結(jié)果是：{0}", t.Result.ToString());
            });
            task.Wait();
            cwt.Wait();
            Console.ReadLine();
            Console.ReadKey();
        }

結(jié)果：

任務(wù)的串行

代碼：

        static void Main(string[] args)
        {
            ConcurrentStack<int> stack = new ConcurrentStack<int>();

            //t1先串行
            var t1 = Task.Factory.StartNew(() =>
            {
                //入棧
                stack.Push(1);
                stack.Push(2);
            });

            //t2,t3并行執(zhí)行
            var t2 = t1.ContinueWith(t =>
            {
                int result;
                //出棧
                stack.TryPop(out result);
                Console.WriteLine("Task t2 result={0},Thread id {1}", result, Thread.CurrentThread.ManagedThreadId);
            });

            //t2,t3并行執(zhí)行
            var t3 = t1.ContinueWith(t =>
            {
                int result;
                //出棧
                stack.TryPop(out result);
                Console.WriteLine("Task t3 result={0},Thread id {1}", result, Thread.CurrentThread.ManagedThreadId);
            });

            //等待t2和t3執(zhí)行完
            Task.WaitAll(t2, t3);

            //t7串行執(zhí)行
            var t4 = Task.Factory.StartNew(() =>
            {
                Console.WriteLine("當(dāng)前的集合數(shù)目：{0},Thread id {1}", stack.Count, Thread.CurrentThread.ManagedThreadId);
            });
            t4.Wait();
            Console.ReadKey();
        }

結(jié)果：

子任務(wù)

代碼：

        public static void Main()
        {
            Task<string[]> parent = new Task<string[]>(state =>
            {
                Console.WriteLine(state);
                string[] result = new string[2];
                //創(chuàng)建并啟動(dòng)子任務(wù)
                new Task(() => { result[0] = "我是子任務(wù)1。"; }, TaskCreationOptions.AttachedToParent).Start();
                new Task(() => { result[1] = "我是子任務(wù)2。"; }, TaskCreationOptions.AttachedToParent).Start();
                return result;
            }, "我是父任務(wù)，並在處理過(guò)程中創(chuàng)建多個(gè)子任務(wù)，所有的子任務(wù)完成以後我才會(huì)開(kāi)始執(zhí)行。");           
            //任務(wù)處理完成后執(zhí)行的操作
            parent.ContinueWith(t =>
            {
                Array.ForEach(t.Result, r => Console.WriteLine(r));
            });
            //啟動(dòng)父任務(wù)
            parent.Start();
            //等待任務(wù)結(jié)束 Wait只能等待父線(xiàn)程結(jié)束,沒(méi)辦法等到父線(xiàn)程的ContinueWith結(jié)束
            //parent.Wait();
            Console.ReadLine();
        }

結(jié)果：

動(dòng)態(tài)并行

代碼：

    class Node
    {
        public Node Left { get; set; }
        public Node Right { get; set; }
        public string Text { get; set; }
    }
    class Program
    {
        static Node GetNode()
        {
            Node root = new Node
            {
                Left = new Node
                {
                    Left = new Node
                    {
                        Text = "L-L"
                    },
                    Right = new Node
                    {
                        Text = "L-R"
                    },
                    Text = "L"
                },
                Right = new Node
                {
                    Left = new Node
                    {
                        Text = "R-L"
                    },
                    Right = new Node
                    {
                        Text = "R-R"
                    },
                    Text = "R"
                },
                Text = "Root"
            };
            return root;
        }

        static void Main(string[] args)
        {
            Node root = GetNode();
            DisplayTree(root);
        }

        static void DisplayTree(Node root)
        {
            var task = Task.Factory.StartNew(() => DisplayNode(root),
                                            CancellationToken.None,
                                            TaskCreationOptions.None,
                                            TaskScheduler.Default);
            task.Wait();
        }

        static void DisplayNode(Node current)
        {

            if (current.Left != null)
                Task.Factory.StartNew(() => DisplayNode(current.Left),
                                            CancellationToken.None,
                                            TaskCreationOptions.AttachedToParent,
                                            TaskScheduler.Default);
            if (current.Right != null)
                Task.Factory.StartNew(() => DisplayNode(current.Right),
                                            CancellationToken.None,
                                            TaskCreationOptions.AttachedToParent,
                                            TaskScheduler.Default);
            Console.WriteLine("當(dāng)前節(jié)點(diǎn)值:{0};處理的Thread ID ={1}", current.Text, Thread.CurrentThread.ManagedThreadId);
        }
    }

結(jié)果：

感謝各位的閱讀，以上就是“C#怎么使用Task.ContinueWith組合任務(wù)”的內(nèi)容了，經(jīng)過(guò)本文的學(xué)習(xí)后，相信大家對(duì)C#怎么使用Task.ContinueWith組合任務(wù)這一問(wèn)題有了更深刻的體會(huì)，具體使用情況還需要大家實(shí)踐驗(yàn)證。這里是億速云，小編將為大家推送更多相關(guān)知識(shí)點(diǎn)的文章，歡迎關(guān)注！