public interface IDownloadProgressListener
{
void OnDownloadSize(long size);
} /// <summary>
/// 下载进度更新显示
/// </summary>
public class DownloadProgressListener : IDownloadProgressListener
{
private long presize = 0;
private DownMsg downMsg = null;
public DownloadProgressListener(DownMsg downmsg)
{
this.downMsg = downmsg;
}
public delegate void DownSendMsg(DownMsg msg);
public DownSendMsg doSendMsg = null;
public void OnDownloadSize(long size)
{
if (downMsg == null)
{
DownMsg downMsg = new DownMsg();
}
//下载速度
if (downMsg.Size == 0)
{
downMsg.Speed = size;
}
else
{
downMsg.Speed = (float)(size - downMsg.Size);
}
if (downMsg.Speed == 0)
{
downMsg.Surplus = -1;
downMsg.SurplusInfo = "未知";
}
else
{
downMsg.Surplus = ((downMsg.Length - downMsg.Size) / downMsg.Speed);
}
downMsg.Size = size; //下载总量
if (size == downMsg.Length)
{
//下载完成
downMsg.Tag = DownStatus.End;
downMsg.SpeedInfo = "0 K";
downMsg.SurplusInfo = "已完成";
}
else
{
//下载中
downMsg.Tag = DownStatus.DownLoad;
}
if (doSendMsg != null) doSendMsg(downMsg);//通知具体调用者下载进度
}
}
/// <summary>
/// 下载类型
/// </summary>
public enum DownStatus
{
Start,
GetLength,
DownLoad,
End,
Error
}
public class DownMsg
{
private int _Length = 0;
private string _LengthInfo = "";
private int _Id = 0;
private DownStatus _Tag = 0;
private long _Size = 0;
private string _SizeInfo = "";
private float _Speed = 0;
private float _Surplus = 0;
private string _SurplusInfo = "";
private string _ErrMessage = "";
private string _SpeedInfo = "";
private double _Progress = 0;
public int Length
{
get
{
return _Length;
}
set
{
_Length = value;
LengthInfo = GetFileSize(value);
}
}
public int Id
{
get
{
return _Id;
}
set
{
_Id = value;
}
}
/// </summary>
public DownStatus Tag
{
get
{
return _Tag;
}
set
{
_Tag = value;
}
}
public long Size
{
get
{
return _Size;
}
set
{
_Size = value;
SizeInfo = GetFileSize(value);
if (Length >= value)
{
Progress = Math.Round((double)value / Length * 100, 2);
}
else
{
Progress = -1;
}
}
}
public float Speed
{
get
{
return _Speed;
}
set
{
_Speed = value;
SpeedInfo = GetFileSize(value);
}
}
public string SpeedInfo
{
get
{
return _SpeedInfo;
}
set
{
_SpeedInfo = value;
}
}
public float Surplus
{
get
{
return _Surplus;
}
set
{
_Surplus = value;
if (value > 0)
{
SurplusInfo = GetDateName((int)Math.Round(value, 0));
}
}
}
public string ErrMessage
{
get
{
return _ErrMessage;
}
set
{
_ErrMessage = value;
}
}
public string SizeInfo
{
get
{
return _SizeInfo;
}
set
{
_SizeInfo = value;
}
}
public string LengthInfo
{
get
{
return _LengthInfo;
}
set
{
_LengthInfo = value;
}
}
public double Progress
{
get
{
return _Progress;
}
set
{
_Progress = value;
}
}
public string SurplusInfo
{
get
{
return _SurplusInfo;
}
set
{
_SurplusInfo = value;
}
}
private string GetFileSize(float Len)
{
float temp = Len;
string[] sizes = { "B", "KB", "MB", "GB" };
int order = 0;
while (temp >= 1024 && order + 1 < sizes.Length)
{
order++;
temp = temp / 1024;
}
return String.Format("{0:0.##} {1}", temp, sizes[order]);
}
private string GetDateName(int Second)
{
float temp = Second;
string suf = "秒";
if (temp > 60)
{
suf = "分钟";
temp /= 60;
if (temp > 60)
{
suf = "小时";
temp /= 60;
if (temp > 24)
{
suf = "天";
temp /= 24;
if (temp > 30)
{
suf = "月";
temp /= 30;
if (temp > 12)
{
suf = "年";
temp /= 12;
}
}
}
}
}
return String.Format("{0:0} {1}", temp, suf);
}
}
}/// <summary>
/// 文件下载
/// </summary>
public class FileDownloader
{
/// <summary>
/// 已下载文件长度
/// </summary>
private long downloadSize = 0;
/// <summary>
/// 原始文件长度
/// </summary>
private long fileSize = 0;
/// <summary>
/// 线程数
/// </summary>
private DownloadThread[] threads;
/// <summary>
/// 本地保存文件
/// </summary>
private string saveFile;
/// <summary>
/// 缓存各线程下载的长度
/// </summary>
public Dictionary<int, long> data = new Dictionary<int, long>();
/// <summary>
/// 每条线程下载的长度
/// </summary>
private long block;
/// <summary>
/// 下载路径
/// </summary>
private String downloadUrl;
/// <summary>
/// 获取线程数
/// </summary>
/// <returns> 获取线程数</returns>
public int getThreadSize()
{
return threads.Length;
}
/// <summary>
/// 获取文件大小
/// </summary>
/// <returns>获取文件大小</returns>
public long getFileSize()
{
return fileSize;
}
/// <summary>
/// 累计已下载大小
/// </summary>
/// <param name="size">累计已下载大小</param>
public void append(long size)
{
//锁定同步..............线程开多了竟然没有同步起来.文件下载已经完毕了,下载总数量却不等于文件实际大小,找了半天原来这里错误的
lock (this)
{
downloadSize += size;
}
}
/// <summary>
/// 更新指定线程最后下载的位置
/// </summary>
/// <param name="threadId">threadId 线程id</param>
/// <param name="pos">最后下载的位置</param>
public void update(int threadId, long pos)
{
if (data.ContainsKey(threadId))
{
this.data[threadId] = pos;
}
else
{
this.data.Add(threadId, pos);
}
}
/// <summary>
/// 构建下载准备,获取文件大小
/// </summary>
/// <param name="downloadUrl">下载路径</param>
/// <param name="fileSaveDir"> 文件保存目录</param>
/// <param name="threadNum">下载线程数</param>
public FileDownloader(string downloadUrl, string fileSaveDir, string filename = "", int threadNum = 3)
{
try
{
if (string.IsNullOrEmpty(filename))
{
filename = Uri.UnescapeDataString(Path.GetFileName(downloadUrl));//获取文件名称 uri 解码中文字符
}
//构建http 请求
this.downloadUrl = downloadUrl;
if (!Directory.Exists(fileSaveDir)) Directory.CreateDirectory(fileSaveDir);
this.threads = new DownloadThread[threadNum];
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(downloadUrl);
request.Referer = downloadUrl.ToString();
request.Method = "GET";
request.UserAgent = "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; SV1; .NET CLR 2.0.1124)";
request.ContentType = "application/octet-stream";
request.Accept = "image/gif, image/jpeg, image/pjpeg, image/pjpeg, application/x-shockwave-flash, application/xaml+xml, application/vnd.ms-xpsdocument, application/x-ms-xbap, application/x-ms-application, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*";
request.Timeout = 20 * 1000;
request.AllowAutoRedirect = true;
using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
{
if (response.StatusCode == HttpStatusCode.OK)
{
this.fileSize = response.ContentLength;//根据响应获取文件大小
if (this.fileSize <= 0) throw new Exception("获取文件大小失败");
if (filename.Length == 0) throw new Exception("获取文件名失败");
this.saveFile = Path.Combine(fileSaveDir, filename); //构建保存文件
//计算每条线程下载的数据长度
this.block = (this.fileSize % this.threads.Length) == 0 ? this.fileSize / this.threads.Length : this.fileSize / this.threads.Length + 1;
}
else
{
throw new Exception("服务器返回状态失败,StatusCode:" + response.StatusCode);
}
}
}
catch (Exception e)
{
throw new Exception("无法连接下载地址");
}
}
/// <summary>
/// 开始下载文件
/// </summary>
/// <param name="listener">监听下载数量的变化,如果不需要了解实时下载的数量,可以设置为null</param>
/// <returns>已下载文件大小</returns>
public long download(IDownloadProgressListener listener)
{
try
{
using (FileStream fstream = new FileStream(this.saveFile, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite))
{
if (this.fileSize > 0) fstream.SetLength(this.fileSize);
fstream.Close();
}
if (this.data.Count != this.threads.Length)
{
this.data.Clear();
for (int i = 0; i < this.threads.Length; i++)
{
this.data.Add(i + 1, 0);//初始化每条线程已经下载的数据长度为0
}
}
for (int i = 0; i < this.threads.Length; i++)
{
//开启线程进行下载
long downLength = this.data[i + 1];
if (downLength < this.block && this.downloadSize < this.fileSize)
{//判断线程是否已经完成下载,否则继续下载 +
this.threads[i] = new DownloadThread(this, downloadUrl, this.saveFile, this.block, this.data[i + 1], i + 1);
this.threads[i].ThreadRun();
}
else
{
this.threads[i] = null;
}
}
bool notFinish = true;//下载未完成
while (notFinish)
{
// 循环判断所有线程是否完成下载
Thread.Sleep(900);
notFinish = false;//假定全部线程下载完成
for (int i = 0; i < this.threads.Length; i++)
{
if (this.threads[i] != null && !this.threads[i].isFinish())
{
//如果发现线程未完成下载
notFinish = true;//设置标志为下载没有完成
if (this.threads[i].getDownLength() == -1)
{
//如果下载失败,再重新下载
this.threads[i] = new DownloadThread(this, downloadUrl, this.saveFile, this.block, this.data[i + 1], i + 1);
this.threads[i].ThreadRun();
}
}
}
if (listener != null)
{
listener.OnDownloadSize(this.downloadSize);//通知目前已经下载完成的数据长度
Console.WriteLine(this.downloadSize);
}
}
}
catch (Exception e)
{
Console.WriteLine(e.Message);
throw new Exception("下载文件失败");
}
return this.downloadSize;
}
} /// <summary>
/// 线程下载
/// </summary>
public class DownloadThread
{
private string saveFilePath;
private string downUrl;
private long block;
private int threadId = -1;
private long downLength;
private bool finish = false;
private FileDownloader downloader;
public DownloadThread(FileDownloader downloader, string downUrl, string saveFile, long block, long downLength, int threadId)
{
this.downUrl = downUrl;
this.saveFilePath = saveFile;
this.block = block;
this.downloader = downloader;
this.threadId = threadId;
this.downLength = downLength;
}
public void ThreadRun()
{
//task
Thread td = new Thread(new ThreadStart(() =>
{
if (downLength < block)//未下载完成
{
try
{
int startPos = (int)(block * (threadId - 1) + downLength);//开始位置
int endPos = (int)(block * threadId - 1);//结束位置
HttpWebRequest request = (HttpWebRequest)WebRequest.Create(downUrl);
request.Referer = downUrl.ToString();
request.Method = "GET";
request.UserAgent = "Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.1; SV1; .NET CLR 2.0.1124)";
request.AllowAutoRedirect = false;
request.ContentType = "application/octet-stream";
request.Accept = "image/gif, image/jpeg, image/pjpeg, image/pjpeg, application/x-shockwave-flash, application/xaml+xml, application/vnd.ms-xpsdocument, application/x-ms-xbap, application/x-ms-application, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword, */*";
request.Timeout = 10 * 1000;
request.AllowAutoRedirect = true;
request.AddRange(startPos, endPos);
//Console.WriteLine(request.Headers.ToString()); //输出构建的http 表头
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
WebResponse wb = request.GetResponse();
using (Stream _stream = wb.GetResponseStream())
{
byte[] buffer = new byte[1024 * 50]; //缓冲区大小
long offset = -1;
using (Stream threadfile = new FileStream(this.saveFilePath, FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite)) //设置文件以共享方式读写,否则会出现当前文件被另一个文件使用.
{
threadfile.Seek(startPos, SeekOrigin.Begin); //移动文件位置
while ((offset = _stream.Read(buffer, 0, buffer.Length)) != 0)
{
//offset 实际下载流大小
downloader.append(offset); //更新已经下载当前总文件大小
threadfile.Write(buffer, 0, (int)offset);
downLength += offset; //设置当前线程已下载位置
downloader.update(this.threadId, downLength);
}
this.finish = true;
}
}
}
catch (Exception e)
{
this.downLength = -1;
}
}
}));
td.IsBackground = true;
td.Start();
}
/// <summary>
/// 下载是否完成
/// </summary>
/// <returns></returns>
public bool isFinish()
{
return finish;
}
/// <summary>
/// 已经下载的内容大小
/// </summary>
/// <returns>如果返回值为-1,代表下载失败</returns>
public long getDownLength()
{
return downLength;
}
} public class MultiDownload
{
public int ThreadNum = 3;
private List<Thread> list = new List<Thread>();
public MultiDownload()
{
doSendMsg += Change;
}
private void Change(DownMsg msg)
{
if (msg.Tag == DownStatus.Error || msg.Tag == DownStatus.End)
{
StartDown(1);
}
}
/// <summary>
/// 添加下载
/// </summary>
/// <param name="DownUrl">下载路径</param>
/// <param name="Dir">保存路径</param>
/// <param name="Id">id</param>
/// <param name="FileName">保存的文件名</param>
public void AddDown(string downUrl, string dir, int id = 0, string fileName = "")
{
Thread tsk = new Thread(() =>
{
download(downUrl, dir, fileName, id);
});
list.Add(tsk);
}
/// <summary>
/// 准备开始下载
/// </summary>
/// <param name="StartNum">启动下载的任务数</param>
public void StartDown(int startNum = 3)
{
for (int i2 = 0; i2 < startNum; i2++)
{
lock (list)
{
for (int i = 0; i < list.Count; i++)
{
if (list[i].ThreadState == System.Threading.ThreadState.Unstarted || list[i].ThreadState == ThreadState.Suspended)
{
list[i].Start();
break;
}
}
}
}
}
/// <summary>
/// 委托回调
/// </summary>
/// <param name="msg"></param>
public delegate void DownloadSendMsg(DownMsg msg);
/// <summary>
/// 委托回调
/// </summary>
public event DownloadSendMsg doSendMsg;
/// <summary>
/// 下载
/// </summary>
/// <param name="path">下载路径</param>
/// <param name="dir">保存文件夹</param>
/// <param name="filename">保存文件名</param>
/// <param name="id"></param>
private void download(string path, string dir, string filename, int id = 0)
{
try
{
DownMsg msg = new DownMsg();
msg.Id = id;
msg.Tag = 0;
doSendMsg(msg);
FileDownloader loader = new FileDownloader(path, dir, filename, ThreadNum);
loader.data.Clear();
msg.Tag = DownStatus.Start;
msg.Length = (int)loader.getFileSize();
doSendMsg(msg);
DownloadProgressListener linstenter = new DownloadProgressListener(msg);
linstenter.doSendMsg = new DownloadProgressListener.DownSendMsg(doSendMsg);
loader.download(linstenter);
}
catch (Exception ex)
{
DownMsg msg = new DownMsg();
msg.Id = id;
msg.Length = 0;
msg.Tag = DownStatus.Error;
msg.ErrMessage = ex.Message;
doSendMsg(msg);
}
}
}
发表评论