/// <summary>
        /// 下一曲
        /// </summary>
        private void NextMusic()
        {
            List <MusicItemViewModel> selectedItem = MusicList.Where(i => i.IsSelected == true).ToList();

            if (selectedItem.Count > 0)
            {
                Playing = selectedItem.First();
                int index = MusicList.IndexOf(Playing);
                if (PlayOrder == 0)
                {
                    if (index < MusicList.Count - 1)
                    {
                        Playing.IsSelected = false;
                        Playing            = MusicList[++index];
                        Playing.IsSelected = true;
                        //System.Threading.Thread.Sleep(100);
                        PlayMusic(Playing.Music);
                    }
                    else
                    {
                        Playing.IsSelected = false;
                        Playing            = MusicList.First();
                        Playing.IsSelected = true;
                        //System.Threading.Thread.Sleep(100);
                        PlayMusic(Playing.Music);
                    }
                }
                else if (PlayOrder == 1)
                {
                    Random random = new Random();
                    int    select;
                    do
                    {
                        select = random.Next(MusicList.Count);
                    } while (select == index);
                    Playing.IsSelected = false;
                    Playing            = MusicList[select];
                    playing.IsSelected = true;
                    PlayMusic(Playing.Music);
                }

                PlayIcon = new BitmapImage(new Uri("/Image/full_pause.png", UriKind.Relative));
            }
        }