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;
}
}
}