TPL——开始一个Task

柔光的暖阳◎ 2022-07-17 03:23 144阅读 0赞

创建Tasks的四个方式：

using System;
    using System.Threading.Tasks;
    namespace Listing_02 {
    class Listing_02 {
    static void Main(string[] args) {
    // use an Action delegate and a named method
    Task task1 = new Task(new Action(printMessage));
    // use a anonymous delegate
    Task task2 = new Task(delegate {
    printMessage();
    });
    // use a lambda expression and a named method
    Task task3 = new Task(() => printMessage());
    // use a lambda expression and an anonymous method
    Task task4 = new Task(() => {
    printMessage();
    });
    task1.Start();
    task2.Start();
    task3.Start();
    task4.Start();
    // wait for input before exiting
    Console.WriteLine("Main method complete. Press enter to finish.");
    Console.ReadLine();
    }
    static void printMessage() {
    Console.WriteLine("Hello World");
    }
    }
    }

创建并且运行Tasks

Task.Factory.StartNew(() => {
    Console.WriteLine("Hello World");
    });

传递参数

using System;
    using System.Threading.Tasks;
    namespace Listing_03 {
    class Listing_03 {
    static void Main(string[] args) {
    // use an Action delegate and a named method
    Task task1 = new Task(new Action<object>(printMessage),
    "First task");
    // use a anonymous delegate
    Task task2 = new Task(delegate (object obj) {
    printMessage(obj);
    }, "Second Task");
    // use a lambda expression and a named method
    // note that parameters to a lambda don’t need
    // to be quoted if there is only one parameter
    Task task3 = new Task((obj) => printMessage(obj), "Third task");
    // use a lambda expression and an anonymous method
    Task task4 = new Task((obj) => {
    printMessage(obj);
    }, "Fourth task");
    task1.Start();
    task2.Start();
    task3.Start();
    task4.Start();
    // wait for input before exiting
    Console.WriteLine("Main method complete. Press enter to finish.");
    Console.ReadLine();
    }
    static void printMessage(object message) {
    Console.WriteLine("Message: {0}", message);
    }
    }
    }

返回结果

using System;
    using System.Threading.Tasks;
    namespace Listing_05 {
    class Listing_05 {
    static void Main(string[] args) {
    // create the task
    Task<int> task1 = new Task<int>(() => {
    int sum = 0;
    for (int i = 0; i < 100; i++) {
    sum += i;
    }
    return sum;
    });
    // start the task
    task1.Start();
    // write out the result
    Console.WriteLine("Result 1: {0}", task1.Result);
    // create the task using state
    Task<int> task2 = new Task<int>(obj => {
    int sum = 0;
    int max = (int)obj;
    for (int i = 0; i < max; i++) {
    sum += i;
    }
    return sum;
    }, 100);
    // start the task
    task2.Start();
    // write out the result
    Console.WriteLine("Result 2: {0}", task2.Result);
    // wait for input before exiting
    Console.WriteLine("Main method complete. Press enter to finish.");
    Console.ReadLine();
    }
    }
    }

在取得结果处，线程会阻塞直至结果返回。