Question

This one is proving very difficult to debug. Lets start with my situation:

I have an ASP.Net MVC3 web app developed with C# using .Net 4. Part of the system allows a user to upload a zip file. This is done fine, and the zip file is saved. There is also a Windows service which will periodically look for new zip files, extract them, do some work and then re-zip them back up. (I use System.IO.Compression for the zipping stuff). This part all works fine, after the processing I end up with a structure something like.

Object1Folder
 \_ Input.zip
 \_ ExtractedFolder
 \_ Output.zip

There is also a feature that allows the user to delete the item, and the requirement is to delete the object folder, in this case “Object1Folder”. Because I need to delete all sub folders and files I have the following recursive function to do the work…

public static void DeleteDirectory(string directoryPath)
{
    string[] files = Directory.GetFiles(directoryPath);
    string[] directories = Directory.GetDirectories(directoryPath);

    foreach (string file in files)
    {
        File.SetAttributes(file, FileAttributes.Normal);
        File.Delete(file);
    }

    foreach (string directory in directories)
    {
        DeleteDirectory(directory);
    }

    Directory.Delete(directoryPath, true);
}

Which is initially called something like…

DeleteDirectory("C:\\Objects\\Object1Folder");

But it doesn’t work! Firstly, there is no error thrown, the code appears to successfully execute, which is annoying. But the result is that only the “Input.zip” file is removed. The “ExtractedFolder” and “Output.zip” file remains.

As far as I can tell, the code is sound. I can’t see that it is a case that it doesn’t attempt to delete the remaining file and folder. Unfortuantely, we don’t have VS installed on the target server so I cannot step through the code and check that it attempts to delete them. Please point out if you can see this being a potential issue though?

My best guesses so far is that it is a permissions issue of some sort. What is interesting (perhaps) is that when I go to manual clean-up the problem (i.e. windows explorer delete of the “Object1Folder” it says “Denied” and asks me to confirm with the admin rights button thing that it does.

I know it’s hard for you all to work the problem out, but I am looking for things that I should check to try and solve this problem. What kind of things should I ensure have correct permissions? What permissions do they need? Is there a good way for me to debug this issue? If something else has a hold of those files (maybe from the extraction process of the Windows Service), how can I check if this is the problem?

Some information about that server that might help: It’s running “Windows Server 2008 R2 Datacenter” with service pack 1 and is 64-bit. The web app is assigned a user that is a member of both “Users” and “IIS_IUSRS”.

Let me know if any of you need some extra information.

Answer 1

Have a look at the eventlog on the server; you might find an exception\error message there.

You could consider using Directory.Delete(path, true) so you delete the folder and all its content in one call (unless I do not understand your code correctly).

Have a look at files being in use. If a file is in use, the OS can’t delete it. So make sure you are releasing all files correctly.

Finally, you can’t force the files to be not in use so you might end up writing a clean script that runs every night to delete unwanted files and folders.