Count specific files from folder

Question

private void button1_Click(object sender, EventArgs e) {
    DialogResult result = folderBrowserDialog1.ShowDialog();
    if (result == DialogResult.OK) {
        string[] files = Directory.GetFiles(folderBrowserDialog1.SelectedPath);
        MessageBox.Show("Files found: " + files.Length.ToString(), "Message");
    }
}

This counts number of files in folder. But I need count for only specific files which are in folder such a .txt or .mp3

possible duplicate of [Find a file with a certain extension in folder](http://stackoverflow.com/questions/3152157/find-a-file-with-a-certain-extension-in-folder) — cbr, Apr 20 '15 at 14:42
If you prefix your code with 4 spaces, it will format nicely. — Ulric, Apr 20 '15 at 14:42

score 1 · Answer 1 · answered Apr 20 '15 at 14:46

1

DirectoryInfo di = new DirectoryInfo(@"C:/temp");

di.GetFiles("test?.txt").Length;

or

di.GetFiles("*.txt").Length;

answered Apr 20 '15 at 14:46

Dominic Scanlan

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score 1 · Answer 2 · answered Apr 20 '15 at 14:48

1

Check if the files' extensions are in your specified collection:

 var validExts = new []{".txt", ".mp3"};

 string[] files = Directory.GetFiles(folderBrowserDialog1.SelectedPath)
            .Where(f => validExts.Contains(Path.GetExtension(f)))
            .ToArray();

answered Apr 20 '15 at 14:48

Jonesopolis

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`HashSet` for `validExts` instead of `String[]` IMHO looks better. – Dmitry Bychenko Apr 20 '15 at 14:57
sure that's better. But the change is probably insignificant on this scale. – Jonesopolis Apr 20 '15 at 14:58

score 0 · Accepted Answer · answered Apr 20 '15 at 14:49

Just union the different extensions:

String[] files = Directory.GetFiles(folderBrowserDialog1.SelectedPath, "*.txt")
          .Union(Directory.GetFiles(folderBrowserDialog1.SelectedPath, "*.mp3"))
          .ToArray();

you can chain as many Union as you want. In case you just want to count the files you don't have to use any array:

private void button1_Click(object sender, EventArgs e) {
  if (folderBrowserDialog1.ShowDialog() == DialogResult.OK)
    MessageBox.Show(Directory.GetFiles(folderBrowserDialog1.SelectedPath, "*.txt")
             .Union(Directory.GetFiles(folderBrowserDialog1.SelectedPath, "*.mp3"))
             .Count(), 
      "Message")
}

Count specific files from folder

3 Answers3