windows media player 列表问题

CWMPMedia m_media;
CWMPPlaylist m_playlist;
m_media = static_cast <CWMPMedia>(m_activeplay.newMedia("d:\\11.mp3"));
m_playlist.appendItem(m_media);
m_activeplay.SetCurrentPlaylist(m_playlist);
m_activeplay.GetControls().play();
每次运行到m_activeplay.SetCurrentPlaylist(m_playlist);时会弹出一对话框，对话框上没有显示内容？怎么回事？
windows media player如何才能实现列表播放？