[转载]一个批量下载图片的c#类(downmoon) – 邀月 – 博客园.1using System;
2using System.Collections.Generic;
3using System.Linq;
4using System.Text;
5using System.IO;
6
7namespace DownloadImagebyXMLListFor2008
8{
9 public class HttpDownLoad
10 {
11 /// <summary>
12 /// HttpWebRequest Property
13 /// </summary>
14 /// <param name=”fileName”></param>
15 /// <param name=”url”></param>
16 /// <param name=”localPath”></param>
17 /// <param name=”timeout”></param>
18 public static void DownloadOneFileByURL(string fileName, string url, string localPath, int timeout)
19 {
20 System.Net.HttpWebRequest request = null;
21 System.Net.HttpWebResponse response = null;
22 request = (System.Net.HttpWebRequest)System.Net.HttpWebRequest.Create(url + fileName);
23 request.Timeout = timeout;//8000 Not work ?
24 response = (System.Net.HttpWebResponse)request.GetResponse();
25 Stream s = response.GetResponseStream();
26 BinaryReader br = new BinaryReader(s);
27 //int length2 = Int32.TryParse(response.ContentLength.ToString(), out 0);
28 int length2 = Int32.Parse(response.ContentLength.ToString());
29 byte[] byteArr = new byte[length2];
30 s.Read(byteArr, 0, length2);
31 if (File.Exists(localPath + fileName)) { File.Delete(localPath + fileName); }
32 if (Directory.Exists(localPath) == false) { Directory.CreateDirectory(localPath); }
33 FileStream fs = File.Create(localPath + fileName);
34 fs.Write(byteArr, 0, length2);
35 fs.Close();
36 br.Close();
37 }
38 /// <summary>
39 ///Web Client Method ,only For Small picture,else large please use FTP
40 /// </summary>
41 /// <param name=”fileName”></param>
42 /// <param name=”url”></param>
43 /// <param name=”localPath”></param>
44 public static void DownloadOneFileByURLWithWebClient(string fileName, string url, string localPath)
45 {
46 System.Net.WebClient wc = new System.Net.WebClient();
47 if (File.Exists(localPath + fileName)) { File.Delete(localPath + fileName); }
48 if (Directory.Exists(localPath) == false) { Directory.CreateDirectory(localPath); }
49 wc.DownloadFile(url + fileName, localPath + fileName);
50 }
51 }
52}
53
需要注意点:
第一 DownloadOneFileByURL方法,有时会下载不了文件,如果文件大于40K就更明显,DownloadOneFileByURLWithWebClient则无此问题。当然,这个大文件也是相对的,如果真的large或huge,请参考FTP。
http://www.cnblogs.com/downmoon/archive/2008/01/29/1057726.html
第二 调用时请用Thread,给出一个示例
2 {
3 if (txtTempFile.Text.Trim().Length == 0)
4 {
5 ErrorStop(“列表文件为空!“); return;
6 }
7 System.Threading.Thread thread = new System.Threading.Thread(new System.Threading.ThreadStart(DownloadAll));
8 thread.Start();
9 }
10 private void DownloadAll()
11 {
12 List<string> ls = GetStringsByFile(txtTempFile.Text.Trim());
13 if (null != ls)
14 {
15
16 foreach (string s in ls)
17 {
18 try
19 {
20 //HttpDownLoad.DownloadOneFileByURL(s, Globals.HttpPreUrl, Globals.LocalPrePath, 8000000);
21 HttpDownLoad.DownloadOneFileByURLWithWebClient(s, Globals.HttpPreUrl, Globals.LocalPrePath);
22 }
23 catch { continue; }
24 }
25 }
26 }
附 WebClient类的说明
http://msdn.microsoft.com/zh-cn/library/system.net.webclient(VS.80).aspx