public void AddTrackFromFolder() { OpenFileDialog openFileDialog = new OpenFileDialog(); openFileDialog.Multiselect = true; openFileDialog.Filter = "MP3 Files (*.mp3)|*.mp3|All files (*.*)|*.*"; DialogResult result = openFileDialog.ShowDialog(); if (result == DialogResult.OK) { string[] files = openFileDialog.FileNames; if (files.Length == 1) { ViewTrack newTrack = playlist.AddTrack(files[0]); if (newTrack != null) { TrackList.Insert(0, newTrack); } } else if (files.Length > 1) { List <ViewTrack> newTracks = playlist.AddTrackList(files); foreach (var track in newTracks) { TrackList.Insert(0, track); } } } }