public void DownloadFile(string url, string fileName)
{
HttpWebRequest request;
HttpWebResponse response = null;
try
{
request = (HttpWebRequest)WebRequest.Create(url);
response = (HttpWebResponse)request.GetResponse();
string range = response.Headers["Content-Range"];
List<int> ran = new List<int>();
ran = GetRange(range);//求出要下的文件分块的起始点，终点，以及总长
int len = ran[2];//分块长度
int offset = ran[0];
DownLoadState x = new DownLoadState(url, response, fileName, offset, len, new DownLoadState.ThreadCallbackHandler(ResponseAsBytes));
//DownLoadState x = new DownLoadState(url,response,offset,len,new DownLoadState.ThreadCallbackHandler(ResponseAsBytes));
// 单线程下载
// x.StartDownloadFileChunk();
x.httpWebClient = this;
//多线程下载
_SmartThreadPool.QueueWorkItem(new Action(x.StartDownloadFileChunk));
//byte[] buffer = this.ResponseAsBytes(url, hwrp, Length, FileName);
}
catch (Exception e)
{
//ExceptionEventArgs.ExceptionActions ea = ExceptionEventArgs.ExceptionActions.Throw;
//if (this.ExceptionOccurrs != null)
//{
// DownLoadState x = new DownLoadState(url, response.ResponseUri.AbsolutePath, fileName, realFileName, offset, blockSize);
// ExceptionEventArgs eea = new ExceptionEventArgs(e, x);
// ExceptionOccurrs(this, eea);
// ea = eea.ExceptionAction;
//}
//if (ea == ExceptionEventArgs.ExceptionActions.Throw)
//{
// if (!(e is WebException) && !(e is SecurityException))
// {
// throw new WebException("net_webclient", e);
// }
// throw;
//}
}
}
internal byte[] ResponseAsBytes(string RequestURL, WebResponse Response, int Length, int ptr, string FileName)
{
// string a = null; //AttachmentName
int filePtr = 0; //整个文件的位置指针
int readBytes = 0;
try
{
//a = Response.Headers["Content-Disposition"]; //attachment
//if (a != null)
//{
// a = a.Substring(a.LastIndexOf("filename=") + 9);
//}
long blockSize = Length; //Response.ContentLength;
bool flagNoLen = false;
if (blockSize == -1)//这里可能有问题
{
flagNoLen = true;
blockSize = 0x10000; //64k
}
byte[] buffer1 = new byte[(int)blockSize];
int blockPtr = 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("-"));
// filePtr = Convert.ToInt32(s);
//}
filePtr = ptr;
int totalRead = 0;
Stream responseStream = Response.GetResponseStream();
do
{
readBytes = responseStream.Read(buffer1, totalRead, ((int)blockSize) - totalRead);
totalRead += readBytes;
if (flagNoLen && (totalRead == blockSize))
{
blockSize += 0x10000;
byte[] buffer2 = new byte[(int)blockSize];
Buffer.BlockCopy(buffer1, 0, buffer2, 0, totalRead);
buffer1 = buffer2;
}
// lock (_SyncLockObject)
// {
// this._bytes += num2;
// }
if (readBytes > 0)
{
if (this.DataReceive != null)
{
byte[] buffer = new byte[readBytes];
Buffer.BlockCopy(buffer1, blockPtr, buffer, 0, buffer.Length);
//写硬盘
DownLoadState dls = new DownLoadState(FileName, filePtr, readBytes, buffer);
DownLoadEventArgs dlea = new DownLoadEventArgs(dls);
//触发事件
this.OnDataReceive(dlea);
//System.Threading.Thread.Sleep(100);
}
blockPtr += readBytes; //本块的位置指针
filePtr += readBytes; //整个文件的位置指针
}
else
{
break;
}
}
while (readBytes != 0);
responseStream.Close();
responseStream = null;
if (flagNoLen)
{
byte[] buffer3 = new byte[totalRead];
Buffer.BlockCopy(buffer1, 0, buffer3, 0, totalRead);
buffer1 = buffer3;
}
return buffer1;
}
catch (Exception e)
{
//ExceptionEventArgs.ExceptionActions ea = ExceptionEventArgs.ExceptionActions.Throw;
//if (this.ExceptionOccurrs != null)
//{
// DownLoadState x = new DownLoadState(RequestURL, Response.ResponseUri.AbsolutePath, FileName, a, filePtr, readBytes);
// ExceptionEventArgs eea = new ExceptionEventArgs(e, x);
// ExceptionOccurrs(this, eea);
// ea = eea.ExceptionAction;
//}
//if (ea == ExceptionEventArgs.ExceptionActions.Throw)
//{
// if (!(e is WebException) && !(e is SecurityException))
// {
// throw new WebException("net_webclient", e);
// }
// throw;
//}
//return null;
return null;
}
}
internal ExceptionEventArgs(System.Exception e, DownLoadState DownloadState)
{
this._Exception = e;
this._DownloadState = DownloadState;
}