当前位置: 首页 > 图文教程 > 网络编程 > ASP.NET > asp.net 需要登陆的网站上下载网页源代码和文件

ASP.NET
ASP.NET开发:简化应用程序的开发支持Web标准
asp.net XMLHttpRequest实现用户注册前的验证
asp.net 页面间传值方法小结
asp.net url重写浅谈
asp.net 验证码生成和刷新及验证
C#精髓 GridView72大绝技 学习gridview的朋友必看
实例说明asp.net中的简单角色权限控制
asp.net网站开发包wq.dll打包下载
js与ASP.NET 中文乱码问题
asp.net checkbox 动态绑定id GridView删除提示
asp.net TextBox回车触发事件 图片在img显示
asp.net 脏字典过滤问题 用正则表达式来过滤脏数据
asp.NET 脏字过滤算法
asp.NET 脏字过滤算法 修改版
asp.net sql 数据库处理函数命令
asp.net Javascript 的几种写法与提示
ASP.NET MVC学习笔记
asp.net 中国身份证号码验证代码 非正则
Asp.net中使用Sqlite数据库的方法
asp.net 中文字符串提交乱码的解决方法

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: 229 ::
收藏到网摘: n/a

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");
}
}