.Net/C#實現支持斷點續傳多線程下載

最近在學習用c#來實現多線程下載，終於讓我google到了些資料，如下是代碼拷貝：
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>
/// 記錄下載的字節位置
/// </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);

}

}

//委託代理線程的所執行的方法簽名一致
public delegate void ThreadCallbackHandler(string S, string s, int I, int i);

//異常處理動做
public enum ExceptionActions

Throw,
CancelAll,
Ignore,
Retry
}

/// <summary>
/// 包含 Exception 事件數據的類
/// </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 事件數據的類
/// </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>
/// 支持斷點續傳多線程下載的類
/// </summary>
public class HttpWebClient

private static object _SyncLockObject = new object();

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

public event DataReceiveEventHandler DataReceive; //接收字節數據事件

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

public event ExceptionEventHandler ExceptionOccurrs; //發生異常事件

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

public event ThreadProcessEventHandler ThreadProcessEnd; //發生多線程處理完畢事件

private int _FileLength; //下載文件的總大小

public int FileLength

get

return _FileLength;

}

/// <summary>
/// 分塊下載文件
/// </summary>
/// <param name="Address">URL 地址</param>
/// <param name="FileName">保存到本地的路徑文件名</param>
/// <param name="ChunksCount">塊數,線程數</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 該常數的值爲 2,147,483,647; 即十六進制的 0x7FFFFFFF

int l = (int) L;

this._FileLength = l;

// 在本地預約空間(居然在多線程下不用先預約空間)
// 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) //塊大小至少爲 128 K 字節

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));
// 單線程下載
// x.StartDownloadFileChunk();

x.httpWebClient = this;
//多線程下載
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>
/// 下載一個文件塊,利用該方法可自行實現多線程斷點續傳
/// </summary>
/// <param name="Address">URL 地址</param>
/// <param name="FileName">保存到本地的路徑文件名</param>
/// <param name="Length">塊大小</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; //整個文件的位置指針
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; //本塊的位置指針

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);
//觸發事件
this.OnDataReceive(dlea);
//System.Threading.Thread.Sleep(100);

p += num2; //本塊的位置指針
P += num2; //整個文件的位置指針

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)

//觸發數據到達事件
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>
/// 測試類
/// </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;

//訂閱 DataReceive　事件
x.DataReceive += new Microshaoft.Utils.HttpWebClient.DataReceiveEventHandler(a.x_DataReceive);
//訂閱 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";
//F = "http://localhost/download/ReSharper1.5.exe";

//F = "http://localhost/mywebapplications/WebApplication7/WebForm1.aspx";
//F = "http://localhost:1080/test/download.jsp";

//F = "http://localhost/download/Webcast20050125_PPT.zip";
//F = "http://www.morequick.com/greenbrowsergb.zip";
//F = "http://localhost/download/test_local.rar";
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 = ""; //用於記錄上次的位數
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() + " 已接收數據: ");
//System.Console.Write( System.DateTime.Now.ToString() + " 已接收數據: ");
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 + " 字節數據 " + s);
//System.Console.Write(bs + i + " 字節數據 " + s);
this.bs = new string('\b', Digits(i) + 3 + Digits(Sender.FileLength) + s.Length);

}

int Digits(int n) //數字所佔位數

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);
//發生異常從新下載至關於斷點續傳,你能夠本身自行選擇處理方式
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");