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.NET filesystemwatcher - was it a file or a directory?

Answer 1

A:

You could interrogate the FileSystemEventArgs.FullPath property to tell if it is a directory or a file.

if (Path.GetFileName(e.FullPath) == String.Empty) 
{
    //it's a directory.
}

To check if it is a file or directory.

Yuriy Faktorovich 2010-07-26 16:09:10

It was deleted, so these calls would fail, no?

Steven Sudit 2010-07-26 16:17:59

@Steven Sudit: You'd have to check the FileSystemEventArgs.ChangeType property first then.

Yuriy Faktorovich 2010-07-26 16:19:37

`File.GetAttributes` throws a `FileNotFoundException` for a deleted file.

Phil 2010-07-26 16:21:36

@Yuriy: That's not going to help any. http://msdn.microsoft.com/en-us/library/t6xf43e0.aspx

Steven Sudit 2010-07-26 16:23:08

@Steven Sudit: modified.

Yuriy Faktorovich 2010-07-26 16:29:28

@Yuriy: I don't think this works. The `Path.GetFileName` has no crystal ball: it just manipulated text.

Steven Sudit 2010-07-26 16:36:40

@Steven Sudit: Can you think of a case where it would not work, the documentation is specifically *If the last character of path is a directory or volume separator character, this method returns String.Empty*. Especially since FullPath *Gets the fully qualifed path of the affected file or directory*.

Yuriy Faktorovich 2010-07-26 16:38:40

This expression doesn't evaluate to true for either a folder or a file.

Phil 2010-07-26 16:49:46

@Phil: How did you test it? It works for me.

Yuriy Faktorovich 2010-07-26 16:56:42

@Yuriy: You're making the false assumption that deleting a folder named "C:\abc\def" will fill `e.FullPath` with "C:\abc\def\". This is *not* the case.

Steven Sudit 2010-07-26 16:58:08

@Steven Sudit: Why not? "C:\abc\def" would not be the fully qualified path, and FullPath returns a fully qualified one.

Yuriy Faktorovich 2010-07-26 17:06:55

@Yuriy: As I've been saying, this turns out not to be the case. Rather than trust your interpretation of the documentation or my memory, I just tested it. I set a FSW on "C:\abc" and created a "def" subdirectory. I found that `e.FullPath` contained "C:\abc\def". Note the lack of any trailing backslash.

Steven Sudit 2010-07-26 17:56:48

Do me a favor: please don't delete this answer. I think it's very educational.

Steven Sudit 2010-07-26 18:25:10

@Steven Sudit Will do, I'd like to test this as well.

Yuriy Faktorovich 2010-07-26 18:36:42

@Yuriy: Yes, please do. We could all benefit from a bit less reliance on authority and a bit more reliance on experimentation.

Steven Sudit 2010-07-26 18:47:20

@yuriy, I created a FSW pointed at a folder copied your code into the delete handler and then created and deleted folders and text files. The handler was fired, but the expression evaluated to false for both files and folders.

Phil 2010-07-27 08:02:22

@Phil: That is really strange, could you pastebin the code?

Yuriy Faktorovich 2010-07-27 14:06:27

@yuriy: Do what?

Phil 2010-07-27 15:02:29

@Phil: Use http://pastebin.com/ to show me your code.

Yuriy Faktorovich 2010-07-27 15:50:32

Answer 2

+1 A:

Here's a simplified and corrected version of fletcher's solution:

namespace Watcher
{
    class Program
    {
        private const string Directory = @"C:\Temp";
        private static FileSystemWatcher _fileWatcher;
        private static FileSystemWatcher _dirWatcher;

        static void Main(string[] args)
        {
             _fileWatcher = new FileSystemWatcher(Directory);
             _fileWatcher.IncludeSubdirectories = true;
             _fileWatcher.NotifyFilter = NotifyFilters.FileName;
             _fileWatcher.EnableRaisingEvents = true;
             _fileWatcher.Deleted += WatcherActivity;

            _dirWatcher = new FileSystemWatcher(Directory);
            _dirWatcher.IncludeSubdirectories = true;
            _dirWatcher.NotifyFilter = NotifyFilters.DirectoryName;
            _dirWatcher.EnableRaisingEvents = true;
            _dirWatcher.Deleted += WatcherActivity;

            Console.ReadLine();
        }

        static void WatcherActivity(object sender, FileSystemEventArgs e)
        {
            if(sender == _dirWatcher)
            {
                Console.WriteLine("Directory:{0}",e.FullPath);
            }
            else
            {
                Console.WriteLine("File:{0}",e.FullPath);
            }
        }
    }
}

Steven Sudit 2010-07-26 18:15:08

+1. Your solution is far simpler

fletcher 2010-07-26 18:20:15

I got the bugs out of it, but you did come up with the idea before I did.

Steven Sudit 2010-07-26 18:24:25

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.NET filesystemwatcher - was it a file or a directory?

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