public static DownloadData Create(string url, string destFolder, ICredentials creds)
{
DownloadData downloadData = new DownloadData();
WebRequest req = GetRequest(url, creds);
try
{
if (req is FtpWebRequest)
{
// get the file size for FTP files
req.Method = WebRequestMethods.Ftp.GetFileSize;
downloadData.response = req.GetResponse();
downloadData.GetFileSize();
// send REST cmd to 0 in case after last file server doesnt cleared it already
//req = GetRequest(url);
//downloadData.response = req.GetResponse();
// new request for downloading the FTP file
req = GetRequest(url, creds);
((FtpWebRequest)req).ContentOffset = 0;
downloadData.response = req.GetResponse();
}
else
{
downloadData.response = req.GetResponse();
downloadData.GetFileSize();
}
}
catch (WebException e)
{
throw e;
}
catch (Exception e)
{
throw new Exception(string.Format("Error downloading \"{0}\": {1}", url, e.Message), e);
}
// Check to make sure the response isn't an error. If it is this method
// will throw exceptions.
ValidateResponse(downloadData.response, url);
// Take the name of the file given to use from the web server.
string fileName = downloadData.response.Headers["Content-Disposition"];
if (fileName != null)
{
int fileLoc = fileName.IndexOf("filename=", StringComparison.OrdinalIgnoreCase);
if (fileLoc != -1)
{
// go past "filename="
fileLoc += 9;
if (fileName.Length > fileLoc)
{
// trim off an ending semicolon if it exists
int end = fileName.IndexOf(';', fileLoc);
if (end == -1)
{
end = fileName.Length - fileLoc;
}
else
{
end -= fileLoc;
}
fileName = fileName.Substring(fileLoc, end).Trim();
}
else
{
fileName = null;
}
}
else
{
fileName = null;
}
}
if (string.IsNullOrEmpty(fileName))
{
// brute force the filename from the url
fileName = Path.GetFileName(downloadData.response.ResponseUri.LocalPath);
}
// trim out non-standard filename characters
if (!string.IsNullOrEmpty(fileName) && fileName.IndexOfAny(invalidFilenameChars.ToArray()) != -1)
{
//make a new string builder (with at least one bad character)
StringBuilder newText = new StringBuilder(fileName.Length - 1);
//remove the bad characters
for (int i = 0; i < fileName.Length; i++)
{
if (invalidFilenameChars.IndexOf(fileName[i]) == -1)
{
newText.Append(fileName[i]);
}
}
fileName = newText.ToString().Trim();
}
// if filename *still* is null or empty, then generate some random temp filename
if (string.IsNullOrEmpty(fileName))
{
fileName = Path.GetFileName(Path.GetTempFileName());
}
string downloadTo = Path.Combine(destFolder, fileName);
downloadData.Filename = downloadTo;
// If we don't know how big the file is supposed to be,
// we can't resume, so delete what we already have if something is on disk already.
if (!downloadData.IsProgressKnown && File.Exists(downloadTo))
{
File.Delete(downloadTo);
}
if (downloadData.IsProgressKnown && File.Exists(downloadTo))
{
// Try and start where the file on disk left off
downloadData.start = new FileInfo(downloadTo).Length;
// If we have a file that's bigger than what is online, then something
// strange happened. Delete it and start again.
if (downloadData.start > downloadData.size)
{
File.Delete(downloadTo);
}
else if (downloadData.start < downloadData.size)
{
// Try and resume by creating a new request with a new start position
downloadData.response.Close();
if (downloadData.response is HttpWebResponse)
{
req = GetRequest(url, creds);
((HttpWebRequest)req).AddRange((int)downloadData.start);
downloadData.response = req.GetResponse();
if (((HttpWebResponse)downloadData.Response).StatusCode != HttpStatusCode.PartialContent)
{
// They didn't support our resume request.
File.Delete(downloadTo);
downloadData.start = 0;
}
}
else
{
req = GetRequest(url, creds);
((FtpWebRequest)req).ContentOffset = (int)downloadData.start;
downloadData.response = req.GetResponse();
if ((downloadData.Response as FtpWebResponse).StatusCode != FtpStatusCode.FileCommandPending)
{
File.Delete(downloadTo);
downloadData.start = 0;
}
}
}
}
return(downloadData);
}
// Begin downloading the file at the specified url, and save it to the given folder.
private void BeginDownload()
{
DownloadData data = null;
FileStream fs = null;
try
{
//start the stopwatch for speed calc
sw.Start();
if (!Directory.Exists(_tempDirectory))
{
Directory.CreateDirectory(_tempDirectory);
}
data = DownloadData.Create(url_, _tempDirectory, _credentials);
//reset the adler
downloadedAdler32.Reset();
DownloadingTo = data.Filename;
if (!File.Exists(DownloadingTo))
{
// create the file
fs = File.Open(DownloadingTo, FileMode.Create, FileAccess.Write);
}
else
{
// read in the existing data to calculate the adler32
if (Adler32 != 0)
{
GetAdler32(DownloadingTo);
}
// apend to an existing file (resume)
fs = File.Open(DownloadingTo, FileMode.Append, FileAccess.Write);
}
// create the download buffer
byte[] buffer = new byte[BufferSize];
int readCount;
// update how many bytes have already been read
sentSinceLastCalc = data.StartPoint; //for BPS calculation
// Only increment once for each %
int LastProgress = 0;
while ((readCount = data.DownloadStream.Read(buffer, 0, BufferSize)) > 0)
{
// update total bytes read
data.StartPoint += readCount;
// update the adler32 value
if (Adler32 != 0)
{
downloadedAdler32.Update(buffer, 0, readCount);
}
// save block to end of file
fs.Write(buffer, 0, readCount);
//calculate download speed
calculateBps(data.StartPoint, data.TotalDownloadSize);
// send progress info
if (data.PercentDone > LastProgress)
{
_onProgress?.Invoke(new DownloadProgressInfo
{
Percentage = data.PercentDone,
DownloadedInBytes = data.TotalDownloadSize,
});
LastProgress = data.PercentDone;
}
}
}
catch (UriFormatException e)
{
throw new Exception(string.Format("Could not parse the URL \"{0}\" - it's either malformed or is an unknown protocol.", url_), e);
}
catch (WebException e)
{
throw e;
}
catch (Exception e)
{
if (string.IsNullOrEmpty(DownloadingTo))
{
throw new Exception(string.Format("Error trying to save file: {0}", e.Message), e);
}
else
{
throw new Exception(string.Format("Error trying to save file \"{0}\": {1}", DownloadingTo, e.Message), e);
}
}
finally
{
if (data != null)
{
data.Close();
}
if (fs != null)
{
fs.Close();
}
}
}