在 C# 中获取 FTP 上的文件大小

Question

我想获取 FTP 上文件的大小。

        //Get File Size
        reqSize = (FtpWebRequest)FtpWebRequest.Create(new Uri(FtpPath + filePath));
        reqSize.Credentials = new NetworkCredential(Username, Password);
        reqSize.Method = WebRequestMethods.Ftp.GetFileSize;
        reqSize.UseBinary = true;
        FtpWebResponse respSize = (FtpWebResponse)reqSize.GetResponse();
        long size = respSize.ContentLength;
        respSize.Close();

我已尝试以下操作，但收到 550 错误。找不到文件/无法访问。但是，以下代码可以工作...

                reqTime = (FtpWebRequest)FtpWebRequest.Create(new Uri(FtpPath + filePath));
                reqTime.Credentials = new NetworkCredential(Username, Password);
                reqTime.Method = WebRequestMethods.Ftp.GetDateTimestamp;
                reqTime.UseBinary = true;
                FtpWebResponse respTime = (FtpWebResponse)reqTime.GetResponse();
                DateTime LastModified = respTime.LastModified;
                respTime.Close();

编辑：这对我不起作用的原因是我的 FTP 服务器不支持 SIZE 方法。

Answer 1

尝试 reqSize.Method = WebRequestMethods.Ftp.GetFileSize;
而不是 GetDateTimestamp

这对我有用：

FtpWebRequest request = (FtpWebRequest)FtpWebRequest.Create(new Uri("ftp://servername/filepath"));
request.Proxy = null;
request.Credentials = new NetworkCredential("user", "password");
request.Method = WebRequestMethods.Ftp.GetFileSize;

FtpWebResponse response = (FtpWebResponse)request.GetResponse();
long size = response.ContentLength;
response.Close();

Answer 2

我试图在下载时获取文件大小。
给出的答案对我来说都不起作用，所以我使用 FtpWebResponse 的 StatusDescription 属性和 DownloadFile 方法做了这个：

int openingBracket = response.StatusDescription.IndexOf("(");
int closingBracket = response.StatusDescription.IndexOf(")");                     
var temporarySubstring = response.StatusDescription.Substring(openingBracket+1, closingBracket - openingBracket);
var fileSize = temporarySubstring.Substring(0, temporarySubstring.IndexOf(" "));

我想有更好的方法可以使用 RegEx 来做到这一点。

Answer 3

//获取 FTP 文件大小的最简单有效的方法。

var size = GetFtpFileSize(new Uri("ftpURL"), new NetworkCredential("用户名", "密码"));

public static long GetFtpFileSize(Uri requestUri, NetworkCredential networkCredential)
{
    //Create ftpWebRequest object with given options to get the File Size. 
    var ftpWebRequest = GetFtpWebRequest(requestUri, networkCredential, WebRequestMethods.Ftp.GetFileSize);

    try { return ((FtpWebResponse)ftpWebRequest.GetResponse()).ContentLength; } //Incase of success it'll return the File Size.
    catch (Exception) { return default(long); } //Incase of fail it'll return default value to check it later.
}
public static FtpWebRequest GetFtpWebRequest(Uri requestUri, NetworkCredential networkCredential, string method = null)
{
    var ftpWebRequest = (FtpWebRequest)WebRequest.Create(requestUri); //Create FtpWebRequest with given Request Uri.
    ftpWebRequest.Credentials = networkCredential; //Set the Credentials of current FtpWebRequest.

    if (!string.IsNullOrEmpty(method))
        ftpWebRequest.Method = method; //Set the Method of FtpWebRequest incase it has a value.
    return ftpWebRequest; //Return the configured FtpWebRequest.
}