问题
The following code is intended to retrieve a file via FTP. However, I'm getting an error with it.
serverPath = "ftp://x.x.x.x/tmp/myfile.txt";
FtpWebRequest request = (FtpWebRequest)WebRequest.Create(serverPath);
request.KeepAlive = true;
request.UsePassive = true;
request.UseBinary = true;
request.Method = WebRequestMethods.Ftp.DownloadFile;
request.Credentials = new NetworkCredential(username, password);
// Read the file from the server & write to destination
using (FtpWebResponse response = (FtpWebResponse)request.GetResponse()) // Error here
using (Stream responseStream = response.GetResponseStream())
using (StreamReader reader = new StreamReader(responseStream))
using (StreamWriter destination = new StreamWriter(destinationFile))
{
destination.Write(reader.ReadToEnd());
destination.Flush();
}
The error is:
The remote server returned an error: (550) File unavailable (e.g., file not found, no access)
The file definitely does exist on the remote machine and I am able to perform this ftp manually (i.e. I have permissions). Can anyone tell me why I might be getting this error?
回答1:
This paragraph from the FptWebRequest class reference might be of interest to you:
The URI may be relative or absolute. If the URI is of the form "ftp://contoso.com/%2fpath" (%2f is an escaped '/'), then the URI is absolute, and the current directory is /path. If, however, the URI is of the form "ftp://contoso.com/path", first the .NET Framework logs into the FTP server (using the user name and password set by the Credentials property), then the current directory is set to /path.
回答2:
I know this is an old Post but I am adding here for future reference. Here is a solution that I found:
private void DownloadFileFTP()
{
string inputfilepath = @"C:\Temp\FileName.exe";
string ftphost = "xxx.xx.x.xxx";
string ftpfilepath = "/Updater/Dir1/FileName.exe";
string ftpfullpath = "ftp://" + ftphost + ftpfilepath;
using (WebClient request = new WebClient())
{
request.Credentials = new NetworkCredential("UserName", "P@55w0rd");
byte[] fileData = request.DownloadData(ftpfullpath);
using (FileStream file = File.Create(inputfilepath))
{
file.Write(fileData, 0, fileData.Length);
file.Close();
}
MessageBox.Show("Download Complete");
}
}
Updated based upon excellent suggestion by Ilya Kogan
回答3:
Easiest way
The most trivial way to download a binary file from an FTP server using .NET framework is using WebClient.DownloadFile:
WebClient client = new WebClient();
client.Credentials = new NetworkCredential("username", "password");
client.DownloadFile(
"ftp://ftp.example.com/remote/path/file.zip", @"C:\local\path\file.zip");
Advanced options
Use FtpWebRequest, only if you need a greater control, that WebClient
does not offer (like TLS/SSL encryption, progress monitoring etc). Easy way is to just copy an FTP response stream to FileStream
using Stream.CopyTo:
FtpWebRequest request =
(FtpWebRequest)WebRequest.Create("ftp://ftp.example.com/remote/path/file.zip");
request.Credentials = new NetworkCredential("username", "password");
request.Method = WebRequestMethods.Ftp.DownloadFile;
using (Stream ftpStream = request.GetResponse().GetResponseStream())
using (Stream fileStream = File.Create(@"C:\local\path\file.zip"))
{
ftpStream.CopyTo(fileStream);
}
Progress monitoring
If you need to monitor a download progress, you have to copy the contents by chunks yourself:
FtpWebRequest request =
(FtpWebRequest)WebRequest.Create("ftp://ftp.example.com/remote/path/file.zip");
request.Credentials = new NetworkCredential("username", "password");
request.Method = WebRequestMethods.Ftp.DownloadFile;
using (Stream ftpStream = request.GetResponse().GetResponseStream())
using (Stream fileStream = File.Create(@"C:\local\path\file.zip"))
{
byte[] buffer = new byte[10240];
int read;
while ((read = ftpStream.Read(buffer, 0, buffer.Length)) > 0)
{
fileStream.Write(buffer, 0, read);
Console.WriteLine("Downloaded {0} bytes", fileStream.Position);
}
}
For GUI progress (WinForms ProgressBar
), see:
FtpWebRequest FTP download with ProgressBar
Downloading folder
If you want to download all files from a remote folder, see
C# Download all files and subdirectories through FTP.
回答4:
I had the same issue!
My solution was to insert the public_html
folder into the download URL.
Real file location on the server:
myhost.com/public_html/myimages/image.png
Web URL:
www.myhost.com/myimages/image.png
回答5:
private static DataTable ReadFTP_CSV()
{
String ftpserver = "ftp://servername/ImportData/xxxx.csv";
FtpWebRequest reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(ftpserver));
reqFTP.Credentials = new NetworkCredential(ftpUserID, ftpPassword);
FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
Stream responseStream = response.GetResponseStream();
// use the stream to read file from FTP
StreamReader sr = new StreamReader(responseStream);
DataTable dt_csvFile = new DataTable();
#region Code
//Add Code Here To Loop txt or CSV file
#endregion
return dt_csvFile;
}
I hope it can help you.
回答6:
FtpWebRequest request = (FtpWebRequest)WebRequest.Create(serverPath);
After this you may use the below line to avoid error..(access denied etc.)
request.Proxy = null;
回答7:
public void download(string remoteFile, string localFile)
{
private string host = "yourhost";
private string user = "username";
private string pass = "passwd";
private FtpWebRequest ftpRequest = null;
private FtpWebResponse ftpResponse = null;
private Stream ftpStream = null;
private int bufferSize = 2048;
try
{
ftpRequest = (FtpWebRequest)FtpWebRequest.Create(host + "/" + remoteFile);
ftpRequest.Credentials = new NetworkCredential(user, pass);
ftpRequest.UseBinary = true;
ftpRequest.UsePassive = true;
ftpRequest.KeepAlive = true;
ftpRequest.Method = WebRequestMethods.Ftp.DownloadFile;
ftpResponse = (FtpWebResponse)ftpRequest.GetResponse();
ftpStream = ftpResponse.GetResponseStream();
FileStream localFileStream = new FileStream(localFile, FileMode.Create);
byte[] byteBuffer = new byte[bufferSize];
int bytesRead = ftpStream.Read(byteBuffer, 0, bufferSize);
try
{
while (bytesRead > 0)
{
localFileStream.Write(byteBuffer, 0, bytesRead);
bytesRead = ftpStream.Read(byteBuffer, 0, bufferSize);
}
}
catch (Exception) { }
localFileStream.Close();
ftpStream.Close();
ftpResponse.Close();
ftpRequest = null;
}
catch (Exception) { }
return;
}
来源:https://stackoverflow.com/questions/2781654/ftpwebrequest-download-file