Question

我正在尝试从FTP下载文件。但是服务器返回错误550（找不到文件，没有访问权限）在我的代码下面，

FtpWebRequest reqFTP;

try
{

    FileStream outputStream = new FileStream("d:/test/" +
                            "\\" +a , FileMode.Create,FileAccess.Write,FileShare.Read);

    reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://example.com/" + " /" + a));

    reqFTP.KeepAlive = false;
    reqFTP.Method = WebRequestMethods.Ftp.DownloadFile;
    reqFTP.UseBinary = true;
    reqFTP.Proxy = null;
    reqFTP.UsePassive = false;
    reqFTP.Credentials = new NetworkCredential("aaaa", "bbbb@1234");


    FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
    // ServicePointManager.ServerCertificateValidationCallback = (sender, certificate, chain, errors) => true;

    Stream ftpStream = response.GetResponseStream();
    long cl = response.ContentLength;
    int bufferSize = 2048;
    int readCount;
    byte[] buffer = new byte[bufferSize];

    readCount = ftpStream.Read(buffer, 0, bufferSize);
    while (readCount > 0)
    {
        outputStream.Write(buffer, 0, readCount);
        readCount = ftpStream.Read(buffer, 0, bufferSize);
    }

    ftpStream.Close();
    outputStream.Close();
    response.Close();
}
catch (WebException ex)
{
    //MessageBox.Show(ex.Message);
    String status = ((FtpWebResponse)ex.Response).StatusDescription;
    MessageBox.Show(status);
}

文件可以在List中显示。虽然没有问题，但在下载时会抛出错误-550，在我的ftp中我有.txt，img，.pdf，.rar，.exe文件格式。

Answer 1

看一下这篇文章：Using the C# WebClient class to upload and download FTP files

基本上，它依赖于执行所有网络工作的WebClient对象。

该文章将其包装在自定义类中，该类与凭证一起使用。

本文的重要部分是：

public byte[] DownloadData(string path)
{
    // Get the object used to communicate with the server.
    WebClient request = new WebClient();

    // Logon to the server using username + password
    request.Credentials = new NetworkCredential(Username, Password);
    return request.DownloadData(BuildServerUri(path));
}

确保凭据和路径正确无误。

Answer 2

我只是在FTP地址中设置了确切的路径，并且设置缓冲区大小也很高，然后它的工作正常。

FtpWebRequest request = (FtpWebRequest)WebRequest.Create("ftp://example.com/file path);

缓冲区大小，

 byte[] buffer = new byte[32 * 1024];

如何使用C＃从FTP下载文件？

2 个答案: