//Version taking string/FileInfo
public async Task <bool> Download(string sourceFilename, FileInfo targetFI, bool PermitOverwrite)
{
//1. check target
if (targetFI.Exists && !(PermitOverwrite))
{
throw (new ApplicationException("Target file already exists"));
}
//2. check source
string target;
if (sourceFilename.Trim() == "")
{
throw (new ApplicationException("File not specified"));
}
else if (sourceFilename.Contains("/"))
{
//treat as a full path
target = AdjustDir(sourceFilename);
}
else
{
//treat as filename only, use current directory
target = CurrentDirectory + sourceFilename;
}
string URI = Hostname + target;
//3. perform copy
System.Net.FtpWebRequest ftp = await GetRequest(URI);
//Set request to download a file in binary mode
ftp.Method = System.Net.WebRequestMethods.Ftp.DownloadFile;
ftp.UseBinary = true;
//open request and get response stream
using (FtpWebResponse response = (FtpWebResponse)await ftp.GetResponseAsync())
{
using (Stream responseStream = response.GetResponseStream())
{
//loop to read & write to file
using (FileStream fs = targetFI.OpenWrite())
{
try
{
byte[] buffer = new byte[2048];
int read = 0;
do
{
read = responseStream.Read(buffer, 0, buffer.Length);
fs.Write(buffer, 0, read);
} while (!(read == 0));
responseStream.Close();
fs.Flush();
fs.Close();
}
catch (Exception)
{
//catch error and delete file only partially downloaded
fs.Close();
//delete target file as it's incomplete
targetFI.Delete();
throw;
}
}
responseStream.Close();
}
response.Close();
}
return(true);
}
private static async Task<bool> TryGetResponseAsync(FtpWebRequest request, FtpStatusCode expectedResult)
{
for (int attempts = 0; attempts < 5; attempts++)
{
var response = (FtpWebResponse)await request.GetResponseAsync();
if (response.StatusCode == expectedResult)
{
return true;
}
}
return false;
}
