使用C#在FTP上获取文件大小

FtpWebRequest request = (FtpWebRequest)WebRequest.Create("ftp://ftp.example.com/file.txt");
request.Method = WebRequestMethods.Ftp.GetFileSize;

request.Credentials = new NetworkCredential("username", "password");

FtpWebResponse response = (FtpWebResponse)request.GetResponse();

long fileSize = response.ContentLength;

response.Close();

using System;
using System.Net;

class Program
{
    static void Main()
    {
        try
        {
            FtpWebRequest request = (FtpWebRequest)WebRequest.Create("ftp://ftp.example.com/file.txt");
            request.Method = WebRequestMethods.Ftp.GetFileSize;
            request.Credentials = new NetworkCredential("username", "password");

            FtpWebResponse response = (FtpWebResponse)request.GetResponse();
            long fileSize = response.ContentLength;

            Console.WriteLine("File Size: " + fileSize + " bytes");

            response.Close();
        }
        catch (Exception ex)
        {
            Console.WriteLine("Error: " + ex.Message);
        }
    }
}