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; } }
