实现支持断点续传多线程下载的 Http Web 客户端工具类

/* .Net/C#: 实现支持断点续传多线程下载的 Http Web 客户端工具类 (C# DIY HttpWebClient) 
 * Reflector 了一下 System.Net.WebClient ,改写或增加了若干: 
 * DownLoad、Upload 相关方法! 
 * DownLoad 相关改动较大! 
 * 增加了 DataReceive、ExceptionOccurrs 事件! 
 * 了解服务器端与客户端交互的 HTTP 协议参阅: 
 * 使文件下载的自定义连接支持 FlashGet 的断点续传多线程链接下载! JSP/Servlet 实现! 
 * http://blog.csdn.net/playyuer/archive/2004/08/02/58430.aspx 
 * 使文件下载的自定义连接支持 FlashGet 的断点续传多线程链接下载! C#/ASP.Net 实现!  
 * http://blog.csdn.net/playyuer/archive/2004/08/02/58281.aspx 
 */ 

2005-03-14 修订:

/* .Net/C#: 实现支持断点续传多线程下载的工具类 
 * Reflector 了一下 System.Net.WebClient ,改写或增加了若干: 
 * DownLoad、Upload 相关方法! 
 * 增加了 DataReceive、ExceptionOccurrs　事件 
 */

namespace Microshaoft.Utils 
{ 
 using System; 
 using System.IO; 
 using System.Net; 
 using System.Text; 
 using System.Security; 
 using System.Threading; 
 using System.Collections.Specialized;

 /// <summary> 
 /// 记录下载的字节位置 
 /// </summary> 
 public class DownLoadState 
 { 
  private string _FileName;

  private string _AttachmentName; 
  private int _Position; 
  private string _RequestURL; 
  private string _ResponseURL; 
  private int _Length;

  private byte[] _Data;

  public string FileName 
  { 
   get 
   { 
    return _FileName; 
   } 
  }

  public int Position 
  { 
   get 
   { 
    return _Position; 
   } 
  }

  public int Length 
  { 
   get 
   { 
    return _Length; 
   } 
  }

  public string AttachmentName 
  { 
   get 
   { 
    return _AttachmentName; 
   } 
  }

  public string RequestURL 
  { 
   get 
   { 
    return _RequestURL; 
   } 
  }

  public string ResponseURL 
  { 
   get 
   { 
    return _ResponseURL; 
   } 
  }

  public byte[] Data 
  { 
   get 
   { 
    return _Data; 
   } 
  }

  internal DownLoadState(string RequestURL, string ResponseURL, string FileName, string AttachmentName, int Position, int Length, byte[] Data) 
  { 
   this._FileName = FileName; 
   this._RequestURL = RequestURL; 
   this._ResponseURL = ResponseURL; 
   this._AttachmentName = AttachmentName; 
   this._Position = Position; 
   this._Data = Data; 
   this._Length = Length; 
  }

  internal DownLoadState(string RequestURL, string ResponseURL, string FileName, string AttachmentName, int Position, int Length, ThreadCallbackHandler tch) 
  { 
   this._RequestURL = RequestURL; 
   this._ResponseURL = ResponseURL; 
   this._FileName = FileName; 
   this._AttachmentName = AttachmentName; 
   this._Position = Position; 
   this._Length = Length; 
   this._ThreadCallback = tch; 
  }

  internal DownLoadState(string RequestURL, string ResponseURL, string FileName, string AttachmentName, int Position, int Length) 
  { 
   this._RequestURL = RequestURL; 
   this._ResponseURL = ResponseURL; 
   this._FileName = FileName; 
   this._AttachmentName = AttachmentName; 
   this._Position = Position; 
   this._Length = Length; 
  }

  private ThreadCallbackHandler _ThreadCallback;

  public HttpWebClient httpWebClient 
  { 
   get 
   { 
    return this._hwc; 
   } 
   set 
   { 
    this._hwc = value; 
   } 
  }

  internal Thread thread 
  { 
   get 
   { 
    return _thread; 
   } 
   set 
   { 
    _thread = value; 
   } 
  }

  private HttpWebClient _hwc; 
  private Thread _thread;

  // 
  internal void StartDownloadFileChunk() 
  { 
   if (this._ThreadCallback != null) 
   { 
    this._ThreadCallback(this._RequestURL, this._FileName, this._Position, this._Length); 
    this._hwc.OnThreadProcess(this._thread); 
   } 
  }

 }

 //委托代理线程的所执行的方法签名一致 
 public delegate void ThreadCallbackHandler(string S, string s, int I, int i);

 //异常处理动作 
 public enum ExceptionActions 
 { 
  Throw, 
  CancelAll, 
  Ignore, 
  Retry 
 }

 /// <summary> 
 /// 包含 Exception 事件数据的类 
 /// </summary> 
 public class ExceptionEventArgs : System.EventArgs 
 { 
  private System.Exception _Exception; 
  private ExceptionActions _ExceptionAction;

  private DownLoadState _DownloadState;

  public DownLoadState DownloadState 
  { 
   get 
   { 
    return _DownloadState; 
   } 
  }

  public Exception Exception 
  { 
   get 
   { 
    return _Exception; 
   } 
  }

  public ExceptionActions ExceptionAction 
  { 
   get 
   { 
    return _ExceptionAction; 
   } 
   set 
   { 
    _ExceptionAction = value; 
   } 
  }

  internal ExceptionEventArgs(System.Exception e, DownLoadState DownloadState) 
  { 
   this._Exception = e; 
   this._DownloadState = DownloadState; 
  } 
 }

 /// <summary> 
 /// 包含 DownLoad 事件数据的类 
 /// </summary> 
 public class DownLoadEventArgs : System.EventArgs 
 { 
  private DownLoadState _DownloadState;

  public DownLoadState DownloadState 
  { 
   get 
   { 
    return _DownloadState; 
   } 
  }

  public DownLoadEventArgs(DownLoadState DownloadState) 
  { 
   this._DownloadState = DownloadState; 
  }

 }

 public class ThreadProcessEventArgs : System.EventArgs 
 { 
  private Thread _thread;

  public Thread thread 
  { 
   get 
   { 
    return this._thread; 
   } 
  }

  public ThreadProcessEventArgs(Thread thread) 
  { 
   this._thread = thread; 
  }

 }

 /// <summary> 
 /// 支持断点续传多线程下载的类 
 /// </summary> 
 public class HttpWebClient 
 { 
  private static object _SyncLockObject = new object();

  public delegate void DataReceiveEventHandler(HttpWebClient Sender, DownLoadEventArgs e);

  public event DataReceiveEventHandler DataReceive; //接收字节数据事件

  public delegate void ExceptionEventHandler(HttpWebClient Sender, ExceptionEventArgs e);

  public event ExceptionEventHandler ExceptionOccurrs; //发生异常事件

  public delegate void ThreadProcessEventHandler(HttpWebClient Sender, ThreadProcessEventArgs e);

  public event ThreadProcessEventHandler ThreadProcessEnd; //发生多线程处理完毕事件

  private int _FileLength; //下载文件的总大小

  public int FileLength 
  { 
   get 
   { 
    return _FileLength; 
   } 
  }

  /// <summary> 
  /// 分块下载文件 
  /// </summary> 
  /// <param name="Address">URL 地址</param> 
  /// <param name="FileName">保存到本地的路径文件名</param> 
  /// <param name="ChunksCount">块数,线程数</param> 
  public void DownloadFile(string Address, string FileName, int ChunksCount) 
  { 
   int p = 0; // position 
   int s = 0; // chunk size 
   string a = null; 
   HttpWebRequest hwrq; 
   HttpWebResponse hwrp = null; 
   try 
   { 
    hwrq = (HttpWebRequest) WebRequest.Create(this.GetUri(Address)); 
    hwrp = (HttpWebResponse) hwrq.GetResponse(); 
    long L = hwrp.ContentLength;

    hwrq.Credentials = this.m_credentials;

    L = ((L == -1) || (L > 0x7fffffff)) ? ((long) 0x7fffffff) : L; //Int32.MaxValue 该常数的值为 2,147,483,647; 即十六进制的 0x7FFFFFFF

    int l = (int) L;

    this._FileLength = l;

    //    在本地预定空间(竟然在多线程下不用先预定空间) 
    //    FileStream sw = new FileStream(FileName, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite); 
    //    sw.Write(new byte[l], 0, l); 
    //    sw.Close(); 
    //    sw = null;

    bool b = (hwrp.Headers["Accept-Ranges"] != null & hwrp.Headers["Accept-Ranges"] == "bytes"); 
    a = hwrp.Headers["Content-Disposition"]; //attachment 
    if (a != null) 
    { 
     a = a.Substring(a.LastIndexOf("filename=") + 9); 
    } 
    else 
    { 
     a = FileName; 
    }

    int ss = s; 
    if (b) 
    { 
     s = l / ChunksCount; 
     if (s < 2 * 64 * 1024) //块大小至少为 128 K 字节 
     { 
      s = 2 * 64 * 1024; 
     } 
     ss = s; 
     int i = 0; 
     while (l > s) 
     { 
      l -= s; 
      if (l < s) 
      { 
       s += l; 
      } 
      if (i++ > 0) 
      { 
       DownLoadState x = new DownLoadState(Address, hwrp.ResponseUri.AbsolutePath, FileName, a, p, s, new ThreadCallbackHandler(this.DownloadFileChunk)); 
       //       单线程下载 
       //       x.StartDownloadFileChunk();

       x.httpWebClient = this; 
       //多线程下载 
       Thread t = new Thread(new ThreadStart(x.StartDownloadFileChunk)); 
       //this.OnThreadProcess(t); 
       t.Start();

      } 
      p += s; 
     } 
     s = ss; 
     byte[] buffer = this.ResponseAsBytes(Address, hwrp, s, FileName); 
     this.OnThreadProcess(Thread.CurrentThread);

     //    lock (_SyncLockObject) 
     //    { 
     //     this._Bytes += buffer.Length; 
     //    } 
    } 
   } 
   catch (Exception e) 
   { 
    ExceptionActions ea = ExceptionActions.Throw; 
    if (this.ExceptionOccurrs != null) 
    { 
     DownLoadState x = new DownLoadState(Address, hwrp.ResponseUri.AbsolutePath, FileName, a, p, s); 
     ExceptionEventArgs eea = new ExceptionEventArgs(e, x); 
     ExceptionOccurrs(this, eea); 
     ea = eea.ExceptionAction; 
    }

    if (ea == ExceptionActions.Throw) 
    { 
     if (!(e is WebException) && !(e is SecurityException)) 
     { 
      throw new WebException("net_webclient", e); 
     } 
     throw; 
    } 
   }

  }

  internal void OnThreadProcess(Thread t) 
  { 
   if (ThreadProcessEnd != null) 
   { 
    ThreadProcessEventArgs tpea = new ThreadProcessEventArgs(t); 
    ThreadProcessEnd(this, tpea); 
   } 
  }

  /// <summary> 
  /// 下载一个文件块,利用该方法可自行实现多线程断点续传 
  /// </summary> 
  /// <param name="Address">URL 地址</param> 
  /// <param name="FileName">保存到本地的路径文件名</param> 
  /// <param name="Length">块大小</param> 
  public void DownloadFileChunk(string Address, string FileName, int FromPosition, int Length) 
  { 
   HttpWebResponse hwrp = null; 
   string a = null; 
   try 
   { 
    //this._FileName = FileName; 
    HttpWebRequest hwrq = (HttpWebRequest) WebRequest.Create(this.GetUri(Address)); 
    //hwrq.Credentials = this.m_credentials; 
    hwrq.AddRange(FromPosition); 
    hwrp = (HttpWebResponse) hwrq.GetResponse(); 
    a = hwrp.Headers["Content-Disposition"]; //attachment 
    if (a != null) 
    { 
     a = a.Substring(a.LastIndexOf("filename=") + 9); 
    } 
    else 
    { 
     a = FileName; 
    }

    byte[] buffer = this.ResponseAsBytes(Address, hwrp, Length, FileName); 
    //   lock (_SyncLockObject) 
    //   { 
    //    this._Bytes += buffer.Length; 
    //   } 
   } 
   catch (Exception e) 
   { 
    ExceptionActions ea = ExceptionActions.Throw; 
    if (this.ExceptionOccurrs != null) 
    { 
     DownLoadState x = new DownLoadState(Address, hwrp.ResponseUri.AbsolutePath, FileName, a, FromPosition, Length); 
     ExceptionEventArgs eea = new ExceptionEventArgs(e, x); 
     ExceptionOccurrs(this, eea); 
     ea = eea.ExceptionAction; 
    }

    if (ea == ExceptionActions.Throw) 
    { 
     if (!(e is WebException) && !(e is SecurityException)) 
     { 
      throw new WebException("net_webclient", e); 
     } 
     throw; 
    } 
   } 
  }

  internal byte[] ResponseAsBytes(string RequestURL, WebResponse Response, long Length, string FileName) 
  { 
   string a = null; //AttachmentName 
   int P = 0; //整个文件的位置指针 
   int num2 = 0; 
   try 
   { 
    a = Response.Headers["Content-Disposition"]; //attachment 
    if (a != null) 
    { 
     a = a.Substring(a.LastIndexOf("filename=") + 9); 
    }

    long num1 = Length; //Response.ContentLength; 
    bool flag1 = false; 
    if (num1 == -1) 
    { 
     flag1 = true; 
     num1 = 0x10000; //64k 
    } 
    byte[] buffer1 = new byte[(int) num1];

    int p = 0; //本块的位置指针

    string s = Response.Headers["Content-Range"]; 
    if (s != null) 
    { 
     s = s.Replace("bytes ", ""); 
     s = s.Substring(0, s.IndexOf("-")); 
     P = Convert.ToInt32(s); 
    } 
    int num3 = 0;

    Stream S = Response.GetResponseStream(); 
    do 
    { 
     num2 = S.Read(buffer1, num3, ((int) num1) - num3);

     num3 += num2; 
     if (flag1 && (num3 == num1)) 
     { 
      num1 += 0x10000; 
      byte[] buffer2 = new byte[(int) num1]; 
      Buffer.BlockCopy(buffer1, 0, buffer2, 0, num3); 
      buffer1 = buffer2; 
     }

     //    lock (_SyncLockObject) 
     //    { 
     //     this._bytes += num2; 
     //    } 
     if (num2 > 0) 
     { 
      if (this.DataReceive != null) 
      { 
       byte[] buffer = new byte[num2]; 
       Buffer.BlockCopy(buffer1, p, buffer, 0, buffer.Length); 
       DownLoadState dls = new DownLoadState(RequestURL, Response.ResponseUri.AbsolutePath, FileName, a, P, num2, buffer); 
       DownLoadEventArgs dlea = new DownLoadEventArgs(dls); 
       //触发事件 
       this.OnDataReceive(dlea); 
       //System.Threading.Thread.Sleep(100);

      } 
      p += num2; //本块的位置指针 
      P += num2; //整个文件的位置指针 
     } 
     else 
     { 
      break; 
     }

    } 
    while (num2 != 0);

    S.Close(); 
    S = null; 
    if (flag1) 
    { 
     byte[] buffer3 = new byte[num3]; 
     Buffer.BlockCopy(buffer1, 0, buffer3, 0, num3); 
     buffer1 = buffer3; 
    } 
    return buffer1; 
   } 
   catch (Exception e) 
   { 
    ExceptionActions ea = ExceptionActions.Throw; 
    if (this.ExceptionOccurrs != null) 
    { 
     DownLoadState x = new DownLoadState(RequestURL, Response.ResponseUri.AbsolutePath, FileName, a, P, num2); 
     ExceptionEventArgs eea = new ExceptionEventArgs(e, x); 
     ExceptionOccurrs(this, eea); 
     ea = eea.ExceptionAction; 
    }

    if (ea == ExceptionActions.Throw) 
    { 
     if (!(e is WebException) && !(e is SecurityException)) 
     { 
      throw new WebException("net_webclient", e); 
     } 
     throw; 
    } 
    return null; 
   } 
  }

  private void OnDataReceive(DownLoadEventArgs e) 
  { 
   //触发数据到达事件 
   DataReceive(this, e); 
  }

  public byte[] UploadFile(string address, string fileName) 
  { 
   return this.UploadFile(address, "POST", fileName, "file"); 
  }

  public string UploadFileEx(string address, string method, string fileName, string fieldName) 
  { 
   return Encoding.ASCII.GetString(UploadFile(address, method, fileName, fieldName)); 
  }

  public byte[] UploadFile(string address, string method, string fileName, string fieldName) 
  { 
   byte[] buffer4; 
   FileStream stream1 = null; 
   try 
   { 
    fileName = Path.GetFullPath(fileName); 
    string text1 = "---------------------" + DateTime.Now.Ticks.ToString("x");

    string text2 = "application/octet-stream";

    stream1 = new FileStream(fileName, FileMode.Open, FileAccess.Read); 
    WebRequest request1 = WebRequest.Create(this.GetUri(address)); 
    request1.Credentials = this.m_credentials; 
    request1.ContentType = "multipart/form-data; boundary=" + text1;

    request1.Method = method; 
    string[] textArray1 = new string[7] {"--", text1, "/r/nContent-Disposition: form-data; name=/"" + fieldName + "/"; filename=/"", Path.GetFileName(fileName), "/"/r/nContent-Type: ", text2, "/r/n/r/n"}; 
    string text3 = string.Concat(textArray1); 
    byte[] buffer1 = Encoding.UTF8.GetBytes(text3); 
    byte[] buffer2 = Encoding.ASCII.GetBytes("/r/n--" + text1 + "/r/n"); 
    long num1 = 0x7fffffffffffffff; 
    try 
    { 
     num1 = stream1.Length; 
     request1.ContentLength = (num1 + buffer1.Length) + buffer2.Length; 
    } 
    catch 
    { 
    } 
    byte[] buffer3 = new byte[Math.Min(0x2000, (int) num1)]; 
    using (Stream stream2 = request1.GetRequestStream()) 
    { 
     int num2; 
     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; 
    WebResponse response1 = request1.GetResponse();

    buffer4 = this.ResponseAsBytes(response1); 
   } 
   catch (Exception exception1) 
   { 
    if (stream1 != null) 
    { 
     stream1.Close(); 
     stream1 = null; 
    } 
    if (!(exception1 is WebException) && !(exception1 is SecurityException)) 
    { 
     //throw new WebException(SR.GetString("net_webclient"), exception1); 
     throw new WebException("net_webclient", exception1); 
    } 
    throw; 
   } 
   return buffer4; 
  }

  private byte[] ResponseAsBytes(WebResponse response) 
  { 
   int num2; 
   long num1 = response.ContentLength; 
   bool flag1 = false; 
   if (num1 == -1) 
   { 
    flag1 = true; 
    num1 = 0x10000; 
   } 
   byte[] buffer1 = new byte[(int) num1]; 
   Stream stream1 = response.GetResponseStream(); 
   int num3 = 0; 
   do 
   { 
    num2 = stream1.Read(buffer1, num3, ((int) num1) - num3); 
    num3 += num2; 
    if (flag1 && (num3 == num1)) 
    { 
     num1 += 0x10000; 
     byte[] buffer2 = new byte[(int) num1]; 
     Buffer.BlockCopy(buffer1, 0, buffer2, 0, num3); 
     buffer1 = buffer2; 
    } 
   } 
   while (num2 != 0); 
   stream1.Close(); 
   if (flag1) 
   { 
    byte[] buffer3 = new byte[num3]; 
    Buffer.BlockCopy(buffer1, 0, buffer3, 0, num3); 
    buffer1 = buffer3; 
   } 
   return buffer1; 
  }

  private NameValueCollection m_requestParameters; 
  private Uri m_baseAddress; 
  private ICredentials m_credentials = CredentialCache.DefaultCredentials;

  public ICredentials Credentials 
  { 
   get 
   { 
    return this.m_credentials; 
   } 
   set 
   { 
    this.m_credentials = value; 
   } 
  }

  public NameValueCollection QueryString 
  { 
   get 
   { 
    if (this.m_requestParameters == null) 
    { 
     this.m_requestParameters = new NameValueCollection(); 
    } 
    return this.m_requestParameters; 
   } 
   set 
   { 
    this.m_requestParameters = value; 
   } 
  }

  public string BaseAddress 
  { 
   get 
   { 
    if (this.m_baseAddress != null) 
    { 
     return this.m_baseAddress.ToString(); 
    } 
    return string.Empty; 
   } 
   set 
   { 
    if ((value == null) || (value.Length == 0)) 
    { 
     this.m_baseAddress = null; 
    } 
    else 
    { 
     try 
     { 
      this.m_baseAddress = new Uri(value); 
     } 
     catch (Exception exception1) 
     { 
      throw new ArgumentException("value", exception1); 
     } 
    } 
   } 
  }

  private Uri GetUri(string path) 
  { 
   Uri uri1; 
   try 
   { 
    if (this.m_baseAddress != null) 
    { 
     uri1 = new Uri(this.m_baseAddress, path); 
    } 
    else 
    { 
     uri1 = new Uri(path); 
    } 
    if (this.m_requestParameters == null) 
    { 
     return uri1; 
    } 
    StringBuilder builder1 = new StringBuilder(); 
    string text1 = string.Empty; 
    for (int num1 = 0; num1 < this.m_requestParameters.Count; num1++) 
    { 
     builder1.Append(text1 + this.m_requestParameters.AllKeys[num1] + "=" + this.m_requestParameters[num1]); 
     text1 = "&"; 
    } 
    UriBuilder builder2 = new UriBuilder(uri1); 
    builder2.Query = builder1.ToString(); 
    uri1 = builder2.Uri; 
   } 
   catch (UriFormatException) 
   { 
    uri1 = new Uri(Path.GetFullPath(path)); 
   } 
   return uri1; 
  }

 }

}

/// <summary> 
/// 测试类 
/// </summary> 
class AppTest 
{ 
 int _k = 0; 
 int _K = 0;

 static void Main() 
 { 
  AppTest a = new AppTest(); 
  Microshaoft.Utils.HttpWebClient x = new Microshaoft.Utils.HttpWebClient();

  a._K = 10;

  //订阅 DataReceive　事件 
  x.DataReceive += new Microshaoft.Utils.HttpWebClient.DataReceiveEventHandler(a.x_DataReceive); 
  //订阅 ExceptionOccurrs　事件 
  x.ExceptionOccurrs += new Microshaoft.Utils.HttpWebClient.ExceptionEventHandler(a.x_ExceptionOccurrs);

  x.ThreadProcessEnd += new Microshaoft.Utils.HttpWebClient.ThreadProcessEventHandler(a.x_ThreadProcessEnd); 
  string F = "http://localhost/download/phpMyAdmin-2.6.1-pl2.zip"; 
  a._F = F; 
  F = "http://localhost/download/jdk-1_5_0_01-windows-i586-p.aa.exe"; 

  string f = F.Substring(F.LastIndexOf("/") + 1);

  //(new System.Threading.Thread(new System.Threading.ThreadStart(new ThreadProcessState(F, @"E:/temp/" + f, 10, x).StartThreadProcess))).Start();

  x.DownloadFile(F, @"E:/temp/temp/" + f, a._K); 
  //  x.DownloadFileChunk(F, @"E:/temp/" + f,15,34556);

  System.Console.ReadLine(); 
  //  string uploadfile = "e://test_local.rar"; 
  //  string str = x.UploadFileEx("http://localhost/phpmyadmin/uploadaction.php", "POST", uploadfile, "file1"); 
  //  System.Console.WriteLine(str); 
  //  System.Console.ReadLine(); 
 }

 string bs = ""; //用于记录上次的位数 
 bool b = false; 
 private int i = 0; 
 private static object _SyncLockObject = new object(); 
 string _F; 
 string _f;

 private void x_DataReceive(Microshaoft.Utils.HttpWebClient Sender, Microshaoft.Utils.DownLoadEventArgs e) 
 { 
  if (!this.b) 
  { 
   lock (_SyncLockObject) 
   { 
    if (!this.b) 
    { 
     System.Console.Write(System.DateTime.Now.ToString() + " 已接收数据:           "); 
     //System.Console.Write( System.DateTime.Now.ToString() + " 已接收数据:           "); 
     this.b = true; 
    } 
   } 
  } 
  string f = e.DownloadState.FileName; 
  if (e.DownloadState.AttachmentName != null) 
   f = System.IO.Path.GetDirectoryName(f) + @"/" + e.DownloadState.AttachmentName;

  this._f = f;

  using (System.IO.FileStream sw = new System.IO.FileStream(f, System.IO.FileMode.OpenOrCreate, System.IO.FileAccess.ReadWrite, System.IO.FileShare.ReadWrite)) 
  { 
   sw.Position = e.DownloadState.Position; 
   sw.Write(e.DownloadState.Data, 0, e.DownloadState.Data.Length); 
   sw.Close(); 
  } 
  string s = System.DateTime.Now.ToString(); 
  lock (_SyncLockObject) 
  { 
   this.i += e.DownloadState.Data.Length; 
   System.Console.Write(bs + "/b/b/b/b/b/b/b/b/b/b" + i + " / " + Sender.FileLength + " 字节数据 " + s); 
   //System.Console.Write(bs + i + " 字节数据 " + s); 
   this.bs = new string('/b', Digits(i) + 3 + Digits(Sender.FileLength) + s.Length); 
  } 
 }

 int Digits(int n) //数字所占位数 
 { 
  n = System.Math.Abs(n); 
  n = n / 10; 
  int i = 1; 
  while (n > 0) 
  { 
   n = n / 10; 
   i++; 
  } 
  return i; 
 }

 private void x_ExceptionOccurrs(Microshaoft.Utils.HttpWebClient Sender, Microshaoft.Utils.ExceptionEventArgs e) 
 { 
  System.Console.WriteLine(e.Exception.Message); 
  //发生异常重新下载相当于断点续传,你可以自己自行选择处理方式 
  Microshaoft.Utils.HttpWebClient x = new Microshaoft.Utils.HttpWebClient(); 
  x.DownloadFileChunk(this._F, this._f, e.DownloadState.Position, e.DownloadState.Length); 
  e.ExceptionAction = Microshaoft.Utils.ExceptionActions.Ignore; 
 }

 private void x_ThreadProcessEnd(Microshaoft.Utils.HttpWebClient Sender, Microshaoft.Utils.ThreadProcessEventArgs e) 
 { 
  //if (e.thread.ThreadState == System.Threading.ThreadState.Stopped) 
  if (this._k ++ == this._K - 1) 
   System.Console.WriteLine("/nend"); 
 } 
}