Why can't I upload using Windows Phone 7 FTP app - windows-phone-7

Question

I want to upload a photo, from the WP7 by FTP application. If I choose the photo, and click the upload button, the server response: 503 bad sequence of commands.
public static void UploadFile(Stream file, string RemoteFile)
{
SocketAsyncEventArgs socketEventArg2 = new SocketAsyncEventArgs();
Socket socket2 = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
int bytes;
Execute("STOR " + RemoteFile);
AutoResetEvent sendCompleted = new AutoResetEvent(false);
socketEventArg2.Completed += delegate {
sendCompleted.Set();
};
file.Seek(0, SeekOrigin.Begin);
while ((bytes = file.Read(buffer2, 0, buffer2.Length)) > 0)
{
socketEventArg2.SetBuffer(buffer2, 0, bytes);
socket2.SendAsync(socketEventArg2);
sendCompleted.WaitOne();
}
file.Close();
}
And this method call:
Stream ss = e.ChosenPhoto;
.
.
for (int i = 0; i < library.Pictures.Count; i++)
{
Stream s = library.Pictures[i].GetImage();
if (s.Length == e.ChosenPhoto.Length)
{
string filename = library.Pictures[i].Name;
MessageBoxResult m = MessageBox.Show(filename, "Upload?", MessageBoxButton.OKCancel);
if (m == MessageBoxResult.OK)
{
Ftp.UploadFile(ss, filename);
}
else
{
return;
}
break;
}
}
The ss variable is a Stream type, the filename variable is a String which is name come into being the remote server.

Answer 1

You have to do more than just call STOR with FTP -- file transfers occur over a separate connection than the command connection. See the response to this question for additional details.
Edit
I just noticed this is for WP7. It looks like you're trying to implement FTP on WP7. Boy are you in for a world of hurt. I have a few suggestions you may consider:
First, the easy, but expensive-up-front way: purchase a third party library that does FTP over sockets such as SecureBlackbox.
Second, the more complex, cheaper-initially-but-possibly-more-expensive-long-term way: consider creating an intermediary web service that accepts the file as a WEB request, then transfers the file using FtpWebRequest server-side. Azure will be your friend there, at least until the uploads start sapping bandwidth.
Third, don't support FTP until FtpWebRequest becomes available for WP7.