我正在使用以下castreceiver当我将我的android发送器连接到chromecast设备时，它显示黑屏并且从不播放视频。https://github.com/googlecast/CastReferencePlayer我在接收器中为widevine设置licenseUrl如下:sampleplayer.CastPlayer.prototype.preloadVideo_=function(mediaInformation){this.log_('preloadVideo_');varself=this;varurl=mediaInformation.contentId;var