//下载文件，是一个单线程的方法，适用于小文件下载，仅支持http方式
private cGlobalParas.DownloadResult DownloadFile(string url, string path)
{
HttpWebRequest wReq = null;
HttpWebResponse wRep = null;
FileStream SaveFileStream = null;
int startingPoint = 0;
try
{
//For using untrusted SSL Certificates
wReq = (HttpWebRequest)HttpWebRequest.Create(url);
wReq.AddRange(startingPoint);
wRep = (HttpWebResponse)wReq.GetResponse();
Stream responseSteam = wRep.GetResponseStream();
if (startingPoint == 0)
{
SaveFileStream = new FileStream(path, FileMode.Create, FileAccess.Write, FileShare.ReadWrite);
}
else
{
SaveFileStream = new FileStream(path, FileMode.Append, FileAccess.Write, FileShare.ReadWrite);
}
int bytesSize;
long fileSize = wRep.ContentLength;
byte[] downloadBuffer = new byte[DEF_PACKET_LENGTH];
while ((bytesSize = responseSteam.Read(downloadBuffer, 0, downloadBuffer.Length)) > 0)
{
SaveFileStream.Write(downloadBuffer, 0, bytesSize);
}
SaveFileStream.Close();
SaveFileStream.Dispose();
wRep.Close();
return(cGlobalParas.DownloadResult.Succeed);
}
catch (System.Exception)
{
return(cGlobalParas.DownloadResult.Err);
}
}
public Task ContentDownloader(string UrlName, string WhereToSave, string FileName, int LimitedBytes)
{
return(Task.Factory.StartNew(() =>
{
try
{
long FileSize = 0;
int BufferSize = LimitedBytes;
long ExistFileSize = 0;
FileStream SaveFileStream;
if (CheckExistingUrl(UrlName) == false)
{
throw new InvalidDataException();
}
/*Check if the file already exist*/
if (File.Exists(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), FileName)))
{
FileInfo FInfo = new FileInfo(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), FileName));
/* Recieve how much size was already downloaded */
ExistFileSize = FInfo.Length;
}
/* If we already have some content in that file, we need to created that file only in append mode and to attach the rest of the content there*/
if (ExistFileSize > 0)
{
SaveFileStream = new FileStream(Path.Combine(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), WhereToSave), FileName), FileMode.Append, FileAccess.Write, FileShare.ReadWrite);
}
/* If that file have size 0 means that is not created so we need to open that file in create mode and add that content*/
else
{
SaveFileStream = new FileStream(Path.Combine(Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.Desktop), WhereToSave), FileName), FileMode.Create, FileAccess.Write, FileShare.ReadWrite);
}
HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(UrlName);
/* Add the content after the existing length */
request.AddRange((int)ExistFileSize);
Stream ResponseStream;
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
ResponseStream = response.GetResponseStream();
FileSize = response.ContentLength;
Console.WriteLine("We need to write " + FileSize + " bytes");
int Recieved;
byte[] buffer = new byte[BufferSize];
int Sum = 0;
while ((Recieved = ResponseStream.Read(buffer, 0, buffer.Length)) > 0)
{
SaveFileStream.Write(buffer, 0, Recieved);
SaveFileStream.Flush();
Sum += Recieved;
}
if (Sum == FileSize)
{
Console.WriteLine("Successfully writed " + Sum + " bytes." + " File " + FileName + " was created");
}
}
catch
{
Console.WriteLine("Unsuccesffully writed file");
}
}
));
}
