private void playRandomSound()
 {
     if (SoundFiles != null && SoundFiles.Any())
     {
         int index = random.Next(SoundFiles.Count);
         PlaySoundComboBox.SelectedIndex = index;
         string filename = SoundFiles[index];
         playSound(filename); //"Cow_Moo-Mike_Koenig-42670858.mp3");
     }
 }
        public void Drop(IDropInfo dropInfo)
        {
            var files = dropDataToFileList(dropInfo);

            if (!IsRunning && files.Count > 0)
            {
                var fileViewModels = files
                                     .Select(file => Path.GetFullPath(file))
                                     .Where(fullName => !SoundFiles.Any(x => x.FullName.Equals(fullName, StringComparison.OrdinalIgnoreCase)))
                                     .Select(fullName => new SoundFileViewModel(fullName))
                                     .ToList();
                foreach (var fileViewModel in fileViewModels)
                {
                    fileViewModel.IsSelected = true;
                    fileViewModel.IsSelectedBaseVolumeFile = true;
                    if (AudioFileManager.OpenFile(fileViewModel.FullName))
                    {
                        SoundFiles.Add(fileViewModel);
                    }
                }
            }
        }