相信用ASP.NET写一个上传文件的网页，大家都会写，但是有没有人想过通过在WinForm中通过HTTP协议上传文件呢？
有些人说要向服务器端上传文件，用FTP协议不是很简单吗？效率又高，为什么还要使用HTTP协议那么麻烦呢？这里面有几个原因：
（1）FTP服务器的部署相对麻烦，还要设置权限，权限设置不对，还会惹来一系列的安全问题。
（2）如果双方都还有防火墙，又不想开发FTP相关的一些端口时，HTTP就会大派用场，就像WEB Services能穿透防火墙一样。
（3）其他的...，还在想呢...
但是使用HTTP也有他的一些问题，例如不能断点续传，大文件上传很难，速度很慢，所以HTTP协议上传的文件大小不应该太大。
说了这么多，原归正传，一般来说，在Winform里通过HTTP上传文件有几种可选的方法：
（1）前面提到的Web Services，就是一种很好的方法，通过编写一个WebMethod，包含有 byte[] 类型的参数，然后调用Web Services的方法，文件内容就会以Base64编码传到服务器上，然后重新保存即可。
Code[WebMethod]
public void UploadFile(byte[] content,string filename)
{
Stream sw = new StreamWriter(
);sw.Close();
}
当然，这种通过Base64编码的方法效率比较低，那么可以采用WSE，支持附件，并以2进制形式传送，效率会更高。
（2）除了通过WebService，另外一种更简单的方法就是通过WebClient或者HttpWebRequest来模拟HTTP的POST动作来实现。这时候首先需要编写一个asp.net web form来响应上传，代码如下：
<%@ Page language="c#" Codebehind="WebForm1.aspx.cs" AutoEventWireup="false" Inherits="UploadFileWeb.WebForm1" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<html>
<head>
<title>WebForm1</title>
<meta name="GENERATOR" Content="Microsoft Visual Studio .NET 7.1">
<meta name="CODE_LANGUAGE" Content="C#">
<meta name="vs_defaultClientScript" content="JavaScript">
<meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5">
</head>
<body>
<form id="Form1" method="post" runat="server">
</form>
</body>
</html>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<html>
<head>
<title>WebForm1</title>
<meta name="GENERATOR" Content="Microsoft Visual Studio .NET 7.1">
<meta name="CODE_LANGUAGE" Content="C#">
<meta name="vs_defaultClientScript" content="JavaScript">
<meta name="vs_targetSchema" content="http://schemas.microsoft.com/intellisense/ie5">
</head>
<body>
<form id="Form1" method="post" runat="server">
</form>
</body>
</html>
Codeusing System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
namespace UploadFileWeb
{
/// <summary>
/// WebForm1 的摘要说明。
/// </summary>
public class WebForm1 : System.Web.UI.Page
{
private void Page_Load(object sender, System.EventArgs e)
{
// 在此处放置用户代码以初始化页面
foreach( string f in Request.Files.AllKeys)
{
HttpPostedFile file = Request.Files[f];
file.SaveAs(@"D:\Temp\" + file.FileName);
}
if( Request.Params["testKey"] != null )
{
Response.Write(Request.Params["testKey"]);
}
}
#region Web 窗体设计器生成的代码
override protected void OnInit(EventArgs e)
{
//
// CODEGEN: 该调用是 ASP.NET Web 窗体设计器所必需的。
//
InitializeComponent();
base.OnInit(e);
}
/// <summary>
/// 设计器支持所需的方法 - 不要使用代码编辑器修改
/// 此方法的内容。
/// </summary>
private void InitializeComponent()
{
this.Load += new System.EventHandler(this.Page_Load);
}
#endregion
}
}
其实这个页面跟我们平常写的asp.net上传文件代码是一样的，在Web 页的Request对象中包含有Files这个对象，里面就包含了通过POST方式上传的所有文件的信息，这时所需要做的就是调用 Request.Files[i].SaveAs方法。
但是怎么让才能在WinForm里面模拟想Web Form POST 数据呢？System.Net命名空间里面提供了两个非常有用的类，一个是WebClient，另外一个是HttpWebRequest类。如果我们不需要通过代理服务器来上传文件，那么非常简单，只需要简单的调用WebClient.UploadFile方法就能实现上传文件：
Codeprivate void button1_Click(object sender, System.EventArgs e)
{
WebClient myWebClient = new WebClient();
myWebClient.UploadFile("http://localhost/UploadFileWeb/WebForm1.aspx","POST",@"D:\Temp\Java\JavaStart\JavaStart2.exe");
}
是不是觉得很简单呢？确实就这么简单。
但是如果要通过代理服务器上传又怎么办呢？那就需要使用到HttpWebRequest，但是该类没有Upload方法，但是幸运的是我们通过Reflector反编译了WebClient.UploadFile方法后，我们发现其内部也是通过WebRequest来实现的，代码如下：
Code
public byte[] UploadFile(string address, string method, string fileName){
string text1; string text2; WebRequest request1; string text3; byte[] buffer1; byte[] buffer2; long num1; byte[] buffer3; int num2; WebResponse response1; byte[] buffer4; DateTime time1; long num3; string[] textArray1; FileStream stream1 = null; try
{ fileName = Path.GetFullPath(fileName); time1 = DateTime.Now; num3 = time1.Ticks; text1 = "---------------------" + num3.ToString("x"); if (this.m_headers == null) { this.m_headers = new WebHeaderCollection();
} text2 = this.m_headers["Content-Type"]; if (text2 != null) { if (text2.ToLower(CultureInfo.InvariantCulture).StartsWith("multipart/")) { throw new WebException(SR.GetString("net_webclient_Multipart")); } } else { text2 = "application/octet-stream"; } this.m_headers["Content-Type"] = "multipart/form-data; boundary=" + text1; this.m_responseHeaders = null; stream1 = new FileStream(fileName, FileMode.Open, FileAccess.Read); request1 = WebRequest.Create(this.GetUri(address)); request1.Credentials = this.Credentials; this.CopyHeadersTo(request1); request1.Method = method; textArray1 = new string[7]; textArray1[0] = "--"; textArray1[1] = text1; textArray1[2] = "\r\nContent-Disposition: form-data; name=\"file\"; filename=\""; textArray1[3] = Path.GetFileName(fileName); textArray1[4] = "\"\r\nContent-Type: "; textArray1[5] = text2; textArray1[6] = "\r\n\r\n"; text3 = string.Concat(textArray1); buffer1 = Encoding.UTF8.GetBytes(text3); buffer2 = Encoding.ASCII.GetBytes("\r\n--" + text1 + "\r\n"); num1 = 9223372036854775807; try { num1 = stream1.Length; request1.ContentLength = ((num1 + ((long) buffer1.Length)) + ((long) buffer2.Length)); } catch { } buffer3 = new byte[Math.Min(((int) 8192), ((int) num1))]; using (Stream stream2 = request1.GetRequestStream()) { stream2.Write(buffer1, 0, buffer1.Length); do { num2 = stream1.Read(buffer3, 0, buffer3.Length); if (num2 != 0) { stream2.Write(buffer3, 0, num2); } } while ((num2 != 0)); stream2.Write(buffer2, 0, buffer2.Length); } stream1.Close(); stream1 = null; response1 = request1.GetResponse(); this.m_responseHeaders = response1.Headers; return this.ResponseAsBytes(response1); } catch (Exception exception1) { if (stream1 != null) { stream1.Close(); stream1 = null; } if ((exception1 is WebException) || (exception1 is SecurityException)) { throw; } throw new WebException(SR.GetString("net_webclient"), exception1); } return buffer4;
}在这段代码里面其实最关键的就是如何模拟POST请求，通过分析代码和监视HTTP，我们可以发现模拟的POST格式如下：
-----------------------8c64f47716481f0 //时间戳
Content-Disposition: form-data; name="file"; filename="a.txt" //文件名
Content-Type: application/octet-stream
//文件的内容
-----------------------8c64f47716481f0
这时候，我们只需自己编码来模拟这么一组数据就行（我们还可以好好借鉴MS的代码呢），以下就是代码（声明一下，我是借用了别人的代码）
Code /**//// <summary> /// 在WinForm中通过HTTP协议向服务器端上传文件 /// </summary> /// <example> /// wwHttp ww = new wwHttp(); /// ww.ProxyAddress = "202.132.156.124"; /// ww.PostMode = 2; /// ww.AddPostKey("testKey","test"); /// ww.AddPostFile("myfile",@"D:\Temp\Java\JavaStart\JavaStart2.jar"); /// string shtml = ww.GetUrlEvents("http://localhost/UploadFileWeb/WebForm1.aspx",409600); /// Console.Write(shtml); /// </example> public class wwHttp { /**//// <summary> /// Fires progress events when using GetUrlEvents() to retrieve a URL. /// </summary> public event OnReceiveDataHandler OnReceiveData; /**//// <summary> /// Determines how data is POSTed when cPostBuffer is set. /// 1 - UrlEncoded /// 2 - Multi-Part form vars /// 4 - XML (raw buffer content type: text/xml) /// </summary> public int PostMode { get { return this.nPostMode; } set { this.nPostMode = value; } } /**//// <summary> /// User name used for Authentication. /// To use the currently logged in user when accessing an NTLM resource you can use "AUTOLOGIN". /// </summary> public string Username { get { return this.cUsername; } set { cUsername = value; } } /**//// <summary> /// Password for Authentication. /// </summary> public string Password { get { return this.cPassword; } set { this.cPassword = value; } } /**//// <summary> /// Address of the Proxy Server to be used. /// Use optional DEFAULTPROXY value to specify that you want to IE's Proxy Settings /// </summary> public string ProxyAddress { get { return this.cProxyAddress; } set { this.cProxyAddress = value; } } /**//// <summary> /// Semicolon separated Address list of the servers the proxy is not used for. /// </summary> public string ProxyBypass { get { return this.cProxyBypass; } set { this.cProxyBypass = value; } } /**//// <summary> /// Username for a password validating Proxy. Only used if the proxy info is set. /// </summary> public string ProxyUsername { get { return this.cProxyUsername; } set { this.cProxyUsername = value; } } /**//// <summary> /// Password for a password validating Proxy. Only used if the proxy info is set. /// </summary> public string ProxyPassword { get { return this.cProxyPassword; } set { this.cProxyPassword = value; } } /**//// <summary> /// Timeout for the Web request in seconds. Times out on connection, read and send operations. /// Default is 30 seconds. /// </summary> public int Timeout { get { return this.nConnectTimeout; } set { this.nConnectTimeout = value; } } /**//// <summary> /// Error Message if the Error Flag is set or an error value is returned from a method. /// </summary> public string ErrorMsg { get { return this.cErrorMsg; } set { this.cErrorMsg = value; } } /**//// <summary> /// Error flag if an error occurred. /// </summary> public bool Error { get { return this.bError; } set { this.bError = value; } } /**//// <summary> /// Determines whether errors cause exceptions to be thrown. By default errors /// are handled in the class and the Error property is set for error conditions. /// (not implemented at this time). /// </summary> public bool ThrowExceptions { get { return bThrowExceptions; } set { this.bThrowExceptions = value; } } /**//// <summary> /// If set to a non-zero value will automatically track cookies. The number assigned is the cookie count. /// </summary> public bool HandleCookies { get { return this.bHandleCookies; } set { this.bHandleCookies = value; } } public CookieCollection Cookies { get { return this.oCookies; } set { this.oCookies = value; } } public HttpWebResponse WebResponse { get { return this.oWebResponse; } set { this.oWebResponse = value; } } public HttpWebRequest WebRequest { get { return this.oWebRequest; } set { this.oWebRequest = value; } } // *** member properties //string cPostBuffer = ""; MemoryStream oPostStream; BinaryWriter oPostData; int nPostMode = 1; int nConnectTimeout = 30; string cUserAgent = "Mozilla/4.0 (compatible; MSIE 6.01; Windows NT 5.0)"; string cUsername = ""; string cPassword = ""; string cProxyAddress = ""; string cProxyBypass = ""; string cProxyUsername = ""; string cProxyPassword = ""; bool bThrowExceptions = false; bool bHandleCookies = false; string cErrorMsg = ""; bool bError = false; HttpWebResponse oWebResponse; HttpWebRequest oWebRequest; CookieCollection oCookies; string cMultiPartBoundary; int webEncode = 936; public wwHttp() { cMultiPartBoundary = string.Format("---------------------------{0}", DateTime.Now.Ticks.ToString("x")); } /**//// <summary> /// Adds POST form variables to the request buffer. /// HttpPostMode determines how parms are handled. /// 1 - UrlEncoded Form Variables. Uses key and value pairs (ie. "Name","Rick") to create URLEncoded content /// 2 - Multi-Part Forms - not supported /// 4 - XML block - Post a single XML block. Pass in as Key (1st Parm) /// other - raw content buffer. Just assign to Key. /// </summary> /// <param name="Key">Key value or raw buffer depending on post type</param> /// <param name="Value">Value to store. Used only in key/value pair modes</param> public void AddPostKey(string Key, byte[] Value) { if (this.oPostData == null) { this.oPostStream = new MemoryStream(); this.oPostData = new BinaryWriter(this.oPostStream); } if (Key == "RESET") { this.oPostStream = new MemoryStream(); this.oPostData = new BinaryWriter(this.oPostStream); } switch (this.nPostMode) { case 1: this.oPostData.Write(Encoding.GetEncoding(webEncode).GetBytes( Key + "=" + HttpUtility.UrlEncode(Value) + "&")); break; case 2: this.oPostData.Write(Encoding.GetEncoding(webEncode).GetBytes( "--" + this.cMultiPartBoundary + "\r\n" + "Content-Disposition: form-data; name=\"" + Key + "\"\r\n\r\n")); this.oPostData.Write(Value); this.oPostData.Write(Encoding.GetEncoding(webEncode).GetBytes("\r\n")); break; default: this.oPostData.Write(Value); break; } } public void AddPostKey(string Key, string Value) { this.AddPostKey(Key, Encoding.GetEncoding(webEncode).GetBytes(Value)); } /**//// <summary> /// Adds a fully self contained POST buffer to the request. /// Works for XML or previously encoded content. /// </summary> /// <param name="PostBuffer"></param> public void AddPostKey(string FullPostBuffer) { this.oPostData.Write(Encoding.GetEncoding(webEncode).GetBytes(FullPostBuffer)); } public bool AddPostFile(string Key, string FileName) { byte[] lcFile; if (this.oPostData == null) { this.oPostStream = new MemoryStream(); this.oPostData = new BinaryWriter(this.oPostStream); } if (this.nPostMode != 2) { this.cErrorMsg = "File upload allowed only with Multi-part forms"; this.bError = true; return false; } try { FileStream loFile = new FileStream(FileName, System.IO.FileMode.Open, System.IO.FileAccess.Read); lcFile = new byte[loFile.Length]; loFile.Read(lcFile, 0, (int)loFile.Length); loFile.Close(); } catch (Exception e) { this.cErrorMsg = e.Message; this.bError = true; return false; } FileInfo fi=new FileInfo(FileName); this.oPostData.Write(Encoding.GetEncoding(webEncode).GetBytes( "--" + this.cMultiPartBoundary + "\r\n" + "Content-Disposition: form-data; name=\"" + Key + "\"; filename=\"" + fi.Name + "\"\r\nContent-Type: " + ReadFileMimeType(fi.Extension) + "\r\n\r\n")); this.oPostData.Write(lcFile); this.oPostData.Write(Encoding.GetEncoding(webEncode).GetBytes("\r\n")); return true; } /**//// <summary> /// 获取文件的MIME类型 /// </summary> /// <param name="fileExtension">文件扩展名</param> /// <returns>MIME类型</returns> private string ReadFileMimeType(string fileExtension) { //set the default content-type const string DEFAULT_CONTENT_TYPE = "application/unknown"; RegistryKey regKey, fileExtKey; string fileContentType; try { //look in HKCR regKey = Registry.ClassesRoot; //look for extension fileExtKey = regKey.OpenSubKey(fileExtension); //retrieve Content Type value fileContentType = fileExtKey.GetValue("Content Type", DEFAULT_CONTENT_TYPE).ToString(); //cleanup fileExtKey = null; regKey = null; } catch { fileContentType = DEFAULT_CONTENT_TYPE; } return fileContentType; } /**//// <summary> /// Return a the result from an HTTP Url into a StreamReader. /// Client code should call Close() on the returned object when done reading. /// </summary> /// <param name="Url">Url to retrieve.</param> /// <param name="WebRequest">An HttpWebRequest object that can be passed in with properties preset.</param> /// <returns></returns> protected StreamReader GetUrlStream(string Url, HttpWebRequest Request) { try { this.bError = false; this.cErrorMsg = ""; if (Request == null) { Request = (HttpWebRequest)System.Net.WebRequest.Create(Url); } Request.UserAgent = this.cUserAgent; Request.Timeout = this.nConnectTimeout * 1000; Request.AllowAutoRedirect = false; // *** Save for external access this.oWebRequest = Request; // *** Handle Security for the request if (this.cUsername.Length > 0) { if (this.cUsername == "AUTOLOGIN") Request.Credentials = CredentialCache.DefaultCredentials; else Request.Credentials = new NetworkCredential(this.cUsername, this.cPassword); } // *** Handle Proxy Server configuration if (this.cProxyAddress.Length > 0) { if (this.cProxyAddress == "DEFAULTPROXY") { Request.Proxy = new WebProxy(); Request.Proxy = WebProxy.GetDefaultProxy(); } else { WebProxy loProxy = new WebProxy(this.cProxyAddress, true); if (this.cProxyBypass.Length > 0) { loProxy.BypassList = this.cProxyBypass.Split(';'); } if (this.cProxyUsername.Length > 0) loProxy.Credentials = new NetworkCredential(this.cProxyUsername, this.cProxyPassword); Request.Proxy = loProxy; } } // *** Handle cookies - automatically re-assign if (this.bHandleCookies) { Request.CookieContainer = new CookieContainer(); if (this.oCookies != null && this.oCookies.Count > 0) { Request.CookieContainer.Add(this.oCookies); } } // *** Deal with the POST buffer if any if (this.oPostData != null) { Request.Method = "POST"; switch (this.nPostMode) { case 1: Request.ContentType = "application/x-www-form-urlencoded"; // strip off any trailing & which can cause problems with some // http servers // if (this.cPostBuffer.EndsWith("&")) // this.cPostBuffer = this.cPostBuffer.Substring(0,this.cPostBuffer.Length-1); break; case 2: Request.ContentType = "multipart/form-data; boundary=" + this.cMultiPartBoundary; this.oPostData.Write(Encoding.GetEncoding(webEncode).GetBytes("--" + this.cMultiPartBoundary + "--\r\n")); break; case 4: Request.ContentType = "text/xml"; break; default: goto case 1; } //Request.Headers[HttpRequestHeader.ContentEncoding] = "GB2312"; Request.ContentLength = oPostStream.Length; Stream loPostData = Request.GetRequestStream(); //loPostData.Write(lcPostData,0,lcPostData.Length); this.oPostStream.WriteTo(loPostData); Console.WriteLine(string.Format("POST {0} HTTP/{1}.{2}", Request.Address.AbsolutePath, Request.ProtocolVersion.Major, Request.Address.AbsolutePath, Request.ProtocolVersion.Minor)); for(int i=0;i<Request.Headers.Count;i++) { Console.WriteLine(string.Format("{0}:{1}", Request.Headers.GetKey(i), Request.Headers.Get(i))); } Console.WriteLine(); byte[] buffer = new byte[this.oPostStream.Length]; buffer = this.oPostStream.ToArray(); Console.Write(Encoding.GetEncoding(webEncode).GetString(buffer, 0, buffer.Length)); //*** Close the memory stream this.oPostStream.Close(); this.oPostStream = null; //*** Close the Binary Writer this.oPostData.Close(); this.oPostData = null; //*** Close Request Stream loPostData.Close(); // *** clear the POST buffer //this.cPostBuffer = ""; } // *** Retrieve the response headers HttpWebResponse Response = (HttpWebResponse)Request.GetResponse(); // ** Save cookies the server sends if (this.bHandleCookies) { if (Response.Cookies.Count > 0) { if (this.oCookies == null) { this.oCookies = Response.Cookies; } else { // ** If we already have cookies update the list foreach (Cookie oRespCookie in Response.Cookies) { bool bMatch = false; foreach (Cookie oReqCookie in this.oCookies) { if (oReqCookie.Name == oRespCookie.Name) { oReqCookie.Value = oRespCookie.Name; bMatch = true; break; // } } // for each ReqCookies if (!bMatch) this.oCookies.Add(oRespCookie); } // for each Response.Cookies } // this.Cookies == null } // if Response.Cookie.Count > 0 } // if this.bHandleCookies = 0 // *** Save the response object for external access this.oWebResponse = Response; Encoding enc; try { if (Response.ContentEncoding.Length > 0) enc = Encoding.GetEncoding(Response.ContentEncoding); else //enc = Encoding.GetEncoding(webEncode); enc = Encoding.Default; } catch { // *** Invalid encoding passed //enc = Encoding.GetEncoding(webEncode); enc = Encoding.Default; } // *** drag to a stream StreamReader strResponse = new StreamReader(Response.GetResponseStream(), enc); return strResponse; } catch (Exception e) { if (this.bThrowExceptions) throw e; this.cErrorMsg = e.Message; this.bError = true; return null; } } /**//// <summary> /// Return a the result from an HTTP Url into a StreamReader. /// Client code should call Close() on the returned object when done reading. /// </summary> /// <param name="Url">Url to retrieve.</param> /// <returns></returns> public StreamReader GetUrlStream(string Url) { HttpWebRequest oHttpWebRequest = null; return this.GetUrlStream(Url, oHttpWebRequest); } /**//// <summary> /// Return a the result from an HTTP Url into a StreamReader. /// Client code should call Close() on the returned object when done reading. /// </summary> /// <param name="Request">A Request object</param> /// <returns></returns> public StreamReader GetUrlStream(HttpWebRequest Request) { return this.GetUrlStream(Request.RequestUri.AbsoluteUri, Request); } /**//// <summary> /// Return a the result from an HTTP Url into a string. /// </summary> /// <param name="Url">Url to retrieve.</param> /// <returns></returns> public string GetUrl(string Url) { StreamReader oHttpResponse = this.GetUrlStream(Url); if (oHttpResponse == null) return ""; string lcResult = oHttpResponse.ReadToEnd(); oHttpResponse.Close(); return lcResult; } /**//// <summary> /// Return a the result from an HTTP Url into a string. /// </summary> /// <param name="Url">Url to retrieve.</param> /// <returns></returns> public byte[] GetUrlBytes(string Url) { StreamReader oHttpResponse = this.GetUrlStream(Url); if (oHttpResponse == null) { return null; } string lcResult = oHttpResponse.ReadToEnd(); oHttpResponse.Close(); return null; } /**//// <summary> /// Retrieves URL with events in the OnReceiveData event. /// </summary> /// <param name="Url"></param> /// <param name="BufferSize"></param> /// <returns></returns> public string GetUrlEvents(string Url, long BufferSize) { StreamReader oHttpResponse = this.GetUrlStream(Url); if (oHttpResponse == null) return ""; long lnSize = BufferSize; if (this.oWebResponse.ContentLength > 0) lnSize = this.oWebResponse.ContentLength; else lnSize = 0; Encoding enc = Encoding.GetEncoding(webEncode); StringBuilder loWriter = new StringBuilder((int)lnSize); char[] lcTemp = new char[BufferSize]; OnReceiveDataEventArgs oArgs = new OnReceiveDataEventArgs(); oArgs.TotalBytes = lnSize; lnSize = 1; int lnCount = 0; long lnTotalBytes = 0; while (lnSize > 0) { lnSize = oHttpResponse.Read(lcTemp, 0, (int)BufferSize); if (lnSize > 0) { loWriter.Append(lcTemp, 0, (int)lnSize); lnCount++; lnTotalBytes += lnSize; // *** Raise an event if hooked up if (this.OnReceiveData != null) { /**//// *** Update the event handler oArgs.CurrentByteCount = lnTotalBytes; oArgs.NumberOfReads = lnCount; oArgs.CurrentChunk = lcTemp; this.OnReceiveData(this, oArgs); // *** Check for cancelled flag if (oArgs.Cancel) goto CloseDown; } } } // while CloseDown: oHttpResponse.Close(); // *** Send Done notification if (this.OnReceiveData != null && !oArgs.Cancel) { // *** Update the event handler oArgs.Done = true; this.OnReceiveData(this, oArgs); } // return lcHtml; return loWriter.ToString(); } public delegate void OnReceiveDataHandler(object sender, OnReceiveDataEventArgs e); public class OnReceiveDataEventArgs { public long CurrentByteCount = 0; public long TotalBytes = 0; public int NumberOfReads = 0; public char[] CurrentChunk; public bool Done = false; public bool Cancel = false; } }在wwHttp这个类里面，不仅仅可以传送文件AddPostFile方法，还可以传送变量AddPostKey方法。
这样，如果我们要通过代理服务器传送文件，就可以编写如下的代码了：
CodewwHttp ww = new wwHttp();
ww.ProxyAddress = "202.132.156.124";
ww.PostMode = 2;
ww.AddPostKey("testKey","test");
ww.AddPostFile("myfile",@"D:\Temp\Java\JavaStart\JavaStart2.jar");
string shtml = ww.GetUrlEvents("http://localhost/UploadFileWeb/WebForm1.aspx",409600);
Console.Write(shtml);
（1）通过Web Services传文件。
（2）如果不需要使用代理，使用WebClient类
（3）如果需要使用代理，使用扩展得到的类wwHttp