[c#]我无法从ftp服务器下载文件，但我可以得到文件列表

Question

Few weeks ago, I set a ftp server in aws windows. And when I tried to download files in ftp server using WebRequestMethods.Ftp.DownloadFile; , it didnt work. But when I tried to get file list from ftp server using WebRequestMethods.Ftp.ListDirectory, it did work, I tried to download files with passive mode, so I thought if there would be something wrong in passive mode. so I used filezilla to connect ftp server with passive mode. and it did work well. I could see file list and upload/download files in ftp server. so Im thinking passive mode is working well at least and it might not be the problem.

And this is the error message that I got when I try to download files from ftp server

System.Net.WebException: Server returned an error: 501 Invalid number of parameters.

It always is this message.

and this is the part of code that I wrote for ftp download connection.

FtpWebRequest requestFTPUploder = (FtpWebRequest)WebRequest.Create(FTP_Address);
requestFTPUploder.UsePassive = true;
requestFTPUploder.Method = WebRequestMethods.Ftp.DownloadFile;
requestFTPUploder.Credentials = new NetworkCredential(User_Name, Password);

The 'FTP_Address' is ip v4 address for connection. I didnt set DNS for my ftp server and it works well for getting list(WebrequestMethods.Ftp.ListDirectory) I added ':20' and ':21' for selection for specific port numbers. And it also worked well for getting file list. Please help. Ive been struggling for this for weeks.

**if i wrote something wrong, sorry for that. This is my first time to actually write something in stackoverflow. Ive always read other people's questions.

Answer 1

I guess requestUploder should be requestDownloader . Moreover WebRequest.Create() is deprecated .

But anyway, try to put a look into FTP_Address variable. It should be named with a name like FTP_url , so it should contain the URL of the file inside the ftp server (not only the ftp server address).

FtpWebRequest request =
    (FtpWebRequest)WebRequest.Create("ftp://ftp.server.com/folder1/folder2/file.zip");