Ccexp.VideoPlayer 无法监听到播放事件, 这是为什么呢?

self.videoPlayer:addEventListener(function(sener, eventType)
if eventType == ccexp.VideoPlayerEvent.PLAYING then
print(111111)
elseif eventType == ccexp.VideoPlayerEvent.PAUSED then
print(222222)
elseif eventType == ccexp.VideoPlayerEvent.STOPPED then
print(333333)
elseif eventType == ccexp.VideoPlayerEvent.COMPLETED then
print(444444)
end
end)