数据下载（

using System;
using System.Collections.Generic;
using System.Text;
using System.Net;
using System.IO;

namespace prjDownLoad
{
 <wbr> <wbr> <wbr> class Program<br> <wbr> <wbr> <wbr> {<br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> static void Main(string[] args)<br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> {<br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> //Version2.<b style="BACKGROUND-COLOR: #880000; COLOR: white">0</b><br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> //使用WebClient来<b style="BACKGROUND-COLOR: #a0ffff; COLOR: black">下载</b><br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> WebClient wc = new WebClient();<br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> //注册当文件<b style="BACKGROUND-COLOR: #a0ffff; COLOR: black">下载</b>完成以后触发的事件<br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> wc.DownloadFileCompleted += new System.ComponentModel.AsyncCompletedEventHandl<wbr>er(wc_DownloadFileCompleted);<br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> //注册文件在<b style="BACKGROUND-COLOR: #a0ffff; COLOR: black">下载</b>过程中触发的事件<br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> wc.DownloadProgressChanged += new DownloadProgressChangedE<wbr>ventHandler(wc_DownloadProgressChanged);<br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> //开始异步<b style="BACKGROUND-COLOR: #a0ffff; COLOR: black">下载</b>文件<br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> wc.<a name="baidusnap0"></a><b style="BACKGROUND-COLOR: #ffff66; COLOR: black">DownloadFileAsync</b>(new Uri("<a href="http://blog.sina.com.cn/dalishuishou">http://blog.sina.com.cn/dalishuishou</a>"), "c:\\bb.txt");<br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> Console.ReadLine();<br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> //这种做法可以在<b style="BACKGROUND-COLOR: #a0ffff; COLOR: black">下载</b>的过程中取消。<br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> //使用CancelAsync可以取消<b style="BACKGROUND-COLOR: #a0ffff; COLOR: black">下载</b><br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr><br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> }</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>

 <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> static void wc_DownloadProgressChanged(object sender, DownloadProgressChangedE<wbr>ventArgs e)<br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> {<br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> //打印<b style="BACKGROUND-COLOR: #a0ffff; COLOR: black">下载</b>的<a name="baidusnap2"></a><b style="BACKGROUND-COLOR: #99ff99; COLOR: black">字节数</b><br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> Console.WriteLine(string.Format("已经<b style="BACKGROUND-COLOR: #a0ffff; COLOR: black">下载</b>了{<b style="BACKGROUND-COLOR: #880000; COLOR: white">0</b>}字节",e.BytesReceived));<br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> //打印<b style="BACKGROUND-COLOR: #a0ffff; COLOR: black">下载</b>的百分比<br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> Console.WriteLine(string.Format("已经完成的百分比：{<b style="BACKGROUND-COLOR: #880000; COLOR: white">0</b>}%",e.ProgressPercentage));<br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> }</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>

 <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> static void wc_DownloadFileCompleted(object sender, System.ComponentModel.AsyncCompletedEventArgs e)<br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> {<br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> Console.WriteLine("<b style="BACKGROUND-COLOR: #a0ffff; COLOR: black">下载</b>完成");<br> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> <wbr> }<br> <wbr> <wbr> <wbr> }<br>}<br></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>