您需要使用 FtpWebRequest 类可以做到这一点。

You'll need to use the FtpWebRequest class to do that one, I think.

FtpWebRequest request = (FtpWebRequest)WebRequest.Create(serverUri);

//If you need to use network credentials
request.Credentials = new NetworkCredential(ftpUsername, ftpPassword); 
//additionally, if you want to use the current user's network credentials, just use:
//System.Net.CredentialCache.DefaultNetworkCredentials

request.Method = WebRequestMethods.Ftp.DeleteFile;
FtpWebResponse response = (FtpWebResponse)request.GetResponse();
Console.WriteLine("Delete status: {0}", response.StatusDescription);  
response.Close();