Code throwing WebException works in .NET 3.5 but not in 4.0

Question

I am writing code to check whether a file exists or not. If the file exists it should throw a WebException. The code is below; if I run this code in .NET 3.5 it throws a WebException, but if use .NET 4.0 the exception is not thrown. I want the exception to be thrown so I can validate the file's existence.

bool IsExists = true;
try
{
    // string ftpServer = "FTP://111.111.111.111/16FebTo15Mar/Backup/MT_Backup/";
    string userName = "gff";
    // string filename = "sachin";
    string password = "gff@123";
    string ftppath= "FTP://111.111.111.111/16FebTo15Mar/Backup/MT_Backup/bh/"; 
                    // Ftpurl + new FileInfo(EmpFldr).Name + "/";

    FtpWebRequest request = (FtpWebRequest)WebRequest.Create(ftppath);
    request.Credentials = new NetworkCredential(userName, password);
    request.Method = WebRequestMethods.Ftp.PrintWorkingDirectory;
    // request.Method = WebRequestMethods.Ftp.MakeDirectory;
    FtpWebResponse response = (FtpWebResponse)request.GetResponse();
}
catch (WebException ex)
{
    IsExists = false;
}
return IsExists;

Not very sure but try [changing the `UsePassive` property](http://stackoverflow.com/questions/4604693/ftp-throws-webexception-only-in-net-4-0) for the ftprequest — V4Vendetta, Feb 24 '12 at 06:37
Is an exception still being thrown? Catch the more general exception and see what it is. — rikitikitik, Feb 24 '12 at 08:23

score 0 · Accepted Answer · edited Jun 20 '20 at 09:12

0

If you want to check for the existence of a file via FTP then check out this answer.

I'd recommend using the following WebRequestMethod instead, this works for me on all servers I tested, even ones which would not return a file size.
WebRequestMethods.Ftp.GetDateTimestamp

edited Jun 20 '20 at 09:12

Community

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answered Feb 24 '12 at 08:26

ta.speot.is

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Also other idea is use `request.Method = WebRequestMethods.Ftp.ListDirectoryDetails;` and parse list to find flie. Since not all FTP web request types are properly implemneted by Microsoft. – Marcin Feb 24 '12 at 08:56

Code throwing WebException works in .NET 3.5 but not in 4.0

1 Answers1