using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; using System.Net; using System.Diagnostics; using System.Threading.Tasks; using System.Threading; namespace 异步编程 { class Program { static void Main(string[] args) { MyDownloadString ds = new MyDownloadString(); ds.DoRun(); Console.ReadKey(); } } class MyDownloadString { Stopwatch sw = new Stopwatch(); public void DoRun() { const int LargeNumber = 6000000; sw.Start(); Task<int> t1 = CountCharacterAsync(1, "http://www.microsoft.com"); // t1.Wait(); 等待这个任务执行完成再去执行其他 Task<int> t2 = CountCharacterAsync(2, "http://www.illustratedcsharp.com"); //t2.Wait(); // Console.WriteLine("3"+t2.Result); CountToAlargeNumber(1, LargeNumber); CountToAlargeNumber(2, LargeNumber); CountToAlargeNumber(3, LargeNumber); CountToAlargeNumber(4, LargeNumber); Console.WriteLine("4"); Console.WriteLine("chars in www.microsoft.com : {0}", t1.Result); Console.WriteLine(" chars in www.illustatecsharp.com : {0}", t2.Result); Console.WriteLine("time in total : " + sw.Elapsed.TotalMilliseconds); } //async 相当于一个标志，标志这个是异步方法，await 指明需要异步执行的地方 ，一个 //异步方法可以包含任意多个await表达式，如果一个不包括编译器会报警, //异步方法的三种返回类型 //Task<T> ，方法返回值，使用Task.Result获得这个返回值 //Task ，如果调用方法不需要从异步方法中返回某个值，但需要检查异步方法的状态,此时使用Task，这是即使异步方法return了某个值，此时也不会获取到 //Void ，只是调用异步方法，没有任何交互 // await 指定一个异步执行的任务（TASK）,创建一个Task的最简单方法是 Task.run() ,它是在不同线程上运行方法 //Task.Delay 不同于thread.sleep 不会阻塞线程，线程可以继续处理其他工作 private async Task<int> CountCharacterAsync(int id ,string site) { WebClient wc = new WebClient(); Console.WriteLine("starting call {0} : {1} ms", id, sw.Elapsed.TotalMilliseconds); string result = await wc.DownloadStringTaskAsync(new Uri(site)); Func<int, int> nf = new Func<int, int>(get10); await Task.Run(() => get10(2)); // 使用lambada表达式逃避task类型的约束 Console.WriteLine(" Call {0} completed : {1} ms", id, sw.Elapsed.TotalMilliseconds); await Task.Delay(5000); return result.Length; } private void CountToAlargeNumber(int id ,int value) { for (long i = 0; i < value; i++) ; Console.WriteLine(" End counting {0} : {1} ms ",id,sw.Elapsed.TotalMilliseconds ); } private int get10(int x) { return 10+x; } } }
using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Threading; using System.Threading.Tasks; using System.Windows.Forms; namespace BackgroundWorker { public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void button1_Click(object sender, EventArgs e) { if (!backgroundWorker1.IsBusy) { backgroundWorker1.RunWorkerAsync(); } } private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e) { for (int i = 1; i < 11; i++) { Thread.Sleep(2000); backgroundWorker1.ReportProgress(i * 10); } } private void backgroundWorker1_ProgressChanged(object sender, ProgressChangedEventArgs e) { progressBar1.Value = e.ProgressPercentage; } } }
