Why the method is not returning files from the main directory and how can i specify many extentions?

Question

This is the code in my method :

t = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
string[] textfiles = ApplyAllFiles(t, "*.txt", ProcessFile).ToArray();

Then i did also:

s = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
string[] textfiles = ApplyAllFiles(s, "*.jpg", ProcessFile).ToArray();

And the ApplyAllFiles method:

static void ProcessFile(string path) {/* ... */}

static IEnumerable<string> ApplyAllFiles(string folder, string searchPattern, Action<string> fileAction)
{
     IEnumerable<string> files = Directory.GetFiles(folder, searchPattern);
     foreach (string file in files)
     {
         fileAction(file);
     }

     foreach (string subDir in Directory.GetDirectories(folder))
     {
         try
         {
             files = files.Concat(ApplyAllFiles(subDir, searchPattern, fileAction));
         }
         catch
         {
              // swallow, log, whatever
         }
      }

      return files;
}

1. Its not getting files from the main directory for example the first main directory is: C:\Users\bout0_000\Documents And i have in this directory some text files. It will get all the text files from sub
   directories in Documents but it will never get the text file that are in C:\Users\bout0_000\Documents

2. How can i get more then one extention for example i did "*.jpg" but i want also to get bmp files png files and gif files.

Answer 1

Why don't you just use SearchOption.AllDirectories? Then you won't need the Concat or the recursion. You could just say

static void ApplyAllFiles(string folder, string searchPattern, Action<string> fileAction)
{
    foreach (string file in Directory.GetFiles(folder, searchPattern, SearchOption.AllDirectories))
        fileAction(file);
}

Here is the overload in question. Or you can use EnumerateFiles.

Unfortunately, the searchPattern argument doesn't support multiple extension patterns, so you'll have to do that yourself. Something like this:

static void ApplyAllFiles(string folder, Action<string> fileAction)
{
    foreach (string file in
             Directory
             .EnumerateFiles(folder, "*", SearchOption.AllDirectories)
             .Where(f => new[] {".jpg", ".txt"}.Contains(Path.GetExtension(f))))
        fileAction(file);
}