title: Populate Listbox with directory contents but only accept certain extensions
body: <p>So, basically I drag in a folder onto the form, and a Listbox populates with the paths of the files inside. I've managed to make the Listbox accept only .MP3 paths, but how can I add more accepted extensions?</p>
  
  <pre><code> Private Sub Form1_DragDrop(sender As System.Object, e As System.Windows.Forms.DragEventArgs) Handles Me.DragDrop
              Dim files() As String = e.Data.GetData(DataFormats.FileDrop)
              For Each path In files
  
             If Directory.Exists(path) Then
                      'Add the contents of the folder to Listbox1
                      ListBox1.Items.AddRange(IO.Directory.GetFiles(path, "*.mp3*"))
  </code></pre>
  
  <p>As you can see in the last line above, paths in the folder having .mp3 extension are accepted. How do I add more accepted extensions, like .avi, .mp4 etc?</p>
  
  <p>I've tried <code>ListBox1.Items.AddRange(IO.Directory.GetFiles(path, "*.mp3*" + "*.mp4*"))</code></p>
  
  <p>I've also tried <code>ListBox1.Items.AddRange(IO.Directory.GetFiles(path, "*.mp3*" , "*.mp4*"))</code></p>
  
  <p>No luck !</p>