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ASP.NET 中的 asp.net 需要登陆的网站上下载网页源代码和文件


出处:互联网   整理: 软晨网(RuanChen.com)   发布: 2009-09-13   浏览: 179 ::
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最近有个项目需要从网络上下载网页信息和文件,并且需要登录后才能下载,所以做了个下载的通用类,供大家参考。 这个是文件下载类:
复制代码 代码如下:

using System;
using System.IO;
using System.Net;
using System.Web;
public class SRWebClient
{
CookieContainer cookie;
public SRWebClient()
{
cookie = new CookieContainer();
}
/// <TgData>
/// <Alias>下载Web源代码</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("下载Web错误", er.ToString());
}
finally
{
res.Close();
S1.Close();
}
return r;
}
/// <TgData>
/// <Alias>下载文件</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("下载文件错误", er.ToString());
}
finally
{
res.Close();
stream.Close();
}
return Filelength;
}
/// <TgData>
/// <Alias>提交数据</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) //包含要提交的数据 就使用Post方式
{
//作为表单请求
request.ContentType = "application/x-www-form-urlencoded";
//方式就是Post
request.Method = "POST";
//把提交的数据换成字节数组
Byte[] B = System.Text.Encoding.Default.GetBytes(postdata);
request.ContentLength = B.Length;
Stream SW = request.GetRequestStream(); //开始提交数据
SW.Write(B, 0, B.Length);
SW.Close();
}
response = request.GetResponse() as HttpWebResponse;
response.Close();
}
}

这个是提交的数据类:
复制代码 代码如下:

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;
}
}

代码贴完了,下面是测试代码,因为有些数据涉及到客户的资料,故隐去
复制代码 代码如下:

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");
}
}