Yield inside Try block

Question

I try to use the recursive built in method:

public IEnumerable<string> Foo(string path)
{
    try
    {
        foreach (string file in Directory.EnumerateFiles(path, "*.*", SearchOption.AllDirectories))
        {
            yield return file;
        }
    }
    catch (Exception)
    { }
}

And received this error:

Cannot yield a value in the body of a try block with a catch clause

How can I use the try-catch in order to avoid me method to crash is I don't have folder permission ?

That piece of code doesn't make a lot of sense. What do you want to do if you catch an exception? After all, the exception block *is* the logic of the method, otherwise you could have just called Directory.EnumerateFiles in your program directly. — nvoigt, May 26 '13 at 09:24
From [Compiler Error CS1626](http://msdn.microsoft.com/en-us/library/cs1x15az(v=vs.90).aspx) `A yield statement is not allowed in a try block if there is a catch clause associated with the try block. To avoid this error, move the yield statement out of the catch clause.` Of course this doesn't completely answer your question. — Soner Gönül, May 26 '13 at 09:27
You mean just put Directory.EnumerateFiles(path, "*.*", SearchOption.AllDirectories) inside foreach and inside Try ? — user2214609, May 26 '13 at 09:46
I'm with @nvoigt here. Explain why you're trying to do this strange thing. Why is there a foreach and a yield return there at all? You already have the collection in hand. Why not simply write `try { return Directory.EnumerateFiles(...); } catch { return Enumerable.Empty(); }` ? Is there an exception on a `MoveNext()` perhaps? — Eric Lippert, May 26 '13 at 14:16

score 1 · Answer 1 · answered May 26 '13 at 09:29

1

public IEnumerable<string> Foo(string path)
{
    var files = new List<string>();
    try
    {
      files.AddRange(Directory.EnumerateFiles(path, "*.*", SearchOption.AllDirectories));
    }
    catch (Exception)
    {
       // this is bad style. You should catch more specific exceptions
    }

    return files;
}

answered May 26 '13 at 09:29

nvoigt

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If you're doing it this (non-lazy) way, you might as well just use `Directory.GetFiles()` instead. – svick May 26 '13 at 09:35

Yield inside Try block

1 Answers1