login

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：

using System;
    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="";
                        
            System.IO.StreamReader S1 = new System.IO.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
            {
                request.ContentType = "application/x-www-form-urlencoded"; //作为表单请求
                request.Method = "POST";        //方式就是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;

                System.IO.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：

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

    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");
            
        }
    }