asp.net 需要登陸的網(wǎng)站上下載網(wǎng)頁源代碼和文件

更新時間：2009年05月26日 02:36:28 作者：

最近有個項目需要從網(wǎng)絡上下載網(wǎng)頁信息和文件，并且需要登錄后才能下載，所以做了個下載的通用類，供大家參考。

這個是文件下載類：

using System; 
using System.IO; 
using System.Net; 
using System.Web; 

public class SRWebClient 
{ 
CookieContainer cookie; 
public SRWebClient() 
{ 
cookie = new CookieContainer(); 
} 

/// <TgData> 
/// <Alias>下載Web源代碼</Alias> 
/// </TgData> 
public string DownloadHtml(string URL) 
{ 
HttpWebRequest request = HttpWebRequest.Create(URL) as HttpWebRequest; 
request.CookieContainer = cookie; 
request.AllowAutoRedirect = false; 

WebResponse res = request.GetResponse(); 
string r = ""; 

StreamReader S1 = new StreamReader(res.GetResponseStream(), System.Text.Encoding.Default); 
try 
{ 
r = S1.ReadToEnd(); 
} 
catch (Exception er) 
{ 
Log l = new Log(); 
l.writelog("下載Web錯誤", er.ToString()); 
} 
finally 
{ 
res.Close(); 
S1.Close(); 
} 

return r; 
} 

/// <TgData> 
/// <Alias>下載文件</Alias> 
/// </TgData> 
public long DownloadFile(string FileURL, string FileSavePath) 
{ 
long Filelength = 0; 
HttpWebRequest req = HttpWebRequest.Create(FileURL) as HttpWebRequest; 

req.CookieContainer = cookie; 
req.AllowAutoRedirect = true; 

HttpWebResponse res = req.GetResponse() as HttpWebResponse; 
System.IO.Stream stream = res.GetResponseStream(); 
try 
{ 
Filelength = res.ContentLength; 

byte[] b = new byte[512]; 

int nReadSize = 0; 
nReadSize = stream.Read(b, 0, 512); 

System.IO.FileStream fs = System.IO.File.Create(FileSavePath); 
try 
{ 
while (nReadSize > 0) 
{ 
fs.Write(b, 0, nReadSize); 
nReadSize = stream.Read(b, 0, 512); 
} 
} 
finally 
{ 
fs.Close(); 
} 
} 
catch (Exception er) 
{ 
Log l = new Log(); 
l.writelog("下載文件錯誤", er.ToString()); 
} 
finally 
{ 
res.Close(); 
stream.Close(); 
} 

return Filelength; 
} 

/// <TgData> 
/// <Alias>提交數(shù)據(jù)</Alias> 
/// </TgData> 
public void Request(string RequestPageURL, RequestData Data) 
{ 
string StrUrl = RequestPageURL; 
HttpWebRequest request = HttpWebRequest.Create(StrUrl) as HttpWebRequest; 
HttpWebResponse response; 

string postdata = Data.GetData(); 
request.Referer = RequestPageURL; 
request.AllowAutoRedirect = false; 
request.UserAgent = "Mozilla/4.0 (compatible; MSIE 6.01; Windows NT 5.0)"; 
request.CookieContainer = cookie; 

Uri u = new Uri(StrUrl); 

if (postdata.Length > 0) //包含要提交的數(shù)據(jù)　就使用Post方式 
{ 
//作為表單請求 
request.ContentType = "application/x-www-form-urlencoded"; 
//方式就是Post 
request.Method = "POST"; 

//把提交的數(shù)據(jù)換成字節(jié)數(shù)組 
Byte[] B = System.Text.Encoding.Default.GetBytes(postdata); 
request.ContentLength = B.Length; 

Stream SW = request.GetRequestStream(); //開始提交數(shù)據(jù) 
SW.Write(B, 0, B.Length); 
SW.Close(); 
} 

response = request.GetResponse() as HttpWebResponse; 
response.Close(); 
} 
} 

這個是提交的數(shù)據(jù)類：

復制代碼代碼如下:

using System.Collections; 
using System.IO; 

public class RequestData 
{ 
ArrayList arr = new ArrayList(); 
public RequestData() 
{ 

} 

public string GetData() 
{ 
string r = ""; 

for (int i = 0; i < arr.Count; i++) 
{ 
data d = (data) arr[i]; 
if (r.Length > 0) 
r += "&"; 
r += d.Field + "=" + d.Value; 
} 
return r; 
} 

public void AddField(string Field, string Value) 
{ 
data a = new data(); 
a.Field = Field; 
a.Value = Value; 

arr.Add(a); 
} 

struct data 
{ 
public string Field, Value; 
} 
} 

代碼貼完了，下面是測試代碼，因為有些數(shù)據(jù)涉及到客戶的資料，故隱去

復制代碼代碼如下:

using NUnit.Framework; 

[TestFixture] 
public class TestWeb 
{ 
[Test] 
public void testDownSEOrder() 
{ 
RequestData data = new RequestData(); 
data.AddField("name", "abc"); 
data.AddField("password", "121"); 

SRWebClient web = new SRWebClient(); 
web.Request("http://127.0.0.1/login.asp", data); 

string s = web.DownloadHtml("http://127.0.0.1/dingdan.asp"); 
System.Console.WriteLine(s); 
} 

[Test] 
public void testDownFile() 
{ 
RequestData data = new RequestData(); 
data.AddField("name", "aaa"); 
data.AddField("password", "bbb"); 

SRWebClient web = new SRWebClient(); 
web.Request("http://127.0.0.1/login.asp", data); 

web.DownloadFile("http://127.0.0.1/download.asp?fileid=1", @"c:\a.txt"); 
} 
} 