Upload files to an FTP server in C#

The following FtpUploadFile method uploads a file to an FTP server. The to_uri parameter is a URI (Uniform Resource Identifier) that identifies the target file as in ftp://www.somewhere.com/test.txt. The other parameters are self-explanatory.

// Use FTP to upload a file.
private void FtpUploadFile(string filename, string to_uri,
    string user_name, string password)
{
    // Get the object used to communicate with the server.
    FtpWebRequest request =
        (FtpWebRequest)WebRequest.Create(to_uri);
    request.Method = WebRequestMethods.Ftp.UploadFile;

    // Get network credentials.
    request.Credentials =
        new NetworkCredential(user_name, password);

    // Read the file's contents into a byte array.
    byte[] bytes = System.IO.File.ReadAllBytes(filename);

    // Write the bytes into the request stream.
    request.ContentLength = bytes.Length;
    using (Stream request_stream = request.GetRequestStream())
    {
        request_stream.Write(bytes, 0, bytes.Length);
        request_stream.Close();
    }
}

The code starts by creating a WebRequest object associated with the URI and by setting its Method property to UploadFile.

Next the program creates a NetworkCredentials object to identify the account being used to upload the file. The example shown in the picture assumes you are using anonymous FTP. If you are using a username and password, fill them in on the main form.

The code uses System.IO.File.ReadAllBytes to read the file’s contents into a byte array and sets the requests object’s ContentLength property to the length of the text to be uploaded. It gets a request stream that it can use to write into the request and writes the bytes into it. After it’s done, the code closes the stream.