C# 开发 FTP 客户端的两种方式

using System.IO;
using System.Net;

public void UploadFile(string serverIp, string userName, string password, string localFilePath, string remoteFileName)
{
    try
    {
        FileInfo fileInfo = new FileInfo(localFilePath);
        // 1. 创建FTP请求
        FtpWebRequest request = (FtpWebRequest)WebRequest.Create($"ftp://{serverIp}/{remoteFileName}");
        request.Method = WebRequestMethods.Ftp.UploadFile;
        // 2. 设置认证信息
        request.Credentials = new NetworkCredential(userName, password);
        request.UseBinary = true; // 使用二进制模式传输
        request.ContentLength = fileInfo.Length;
        // 3. 读取本地文件并写入请求流
        byte[] buffer = new byte[2048];
        using (FileStream fs = fileInfo.OpenRead())
        using (Stream requestStream = request.GetRequestStream())
        {
            int bytesRead;
            while ((bytesRead = fs.Read(buffer, 0, buffer.Length)) > 0)
            {
                requestStream.Write(buffer, 0, bytesRead);
            }
        }
        // 4. 获取服务器响应（可选，用于确认）
        using (FtpWebResponse response = (FtpWebResponse)request.GetResponse())
        {
            Console.WriteLine($"上传完成，状态: {response.StatusDescription}");
        }
    }
    catch (Exception ex)
    {
        Console.WriteLine($"上传失败: {ex.Message}");
    }
}

using FluentFTP;
using System.IO;
using System.Threading.Tasks;

public static async Task DownloadFileAsync()
{
    // 1. 创建并配置客户端
    var client = new AsyncFtpClient("ftp.server.com", "username", "password");
    // 2. 连接到服务器
    await client.Connect();
    // 3. 执行下载
    await client.DownloadFile(@"C:\local\path\to\file.zip", "/remote/path/file.zip");
    // 4. 断开连接
    await client.Disconnect();
}