判断APP是否进入后台

 //监控APP是否进入后台

    [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(clickAppInToBackground) name:UIApplicationDidEnterBackgroundNotification object:nil];

#pragma mark - APP进图后台 视频播放暂停

-(void)clickAppInToBackground

{

    NSLog(@"APP进图后台 视频播放暂停");

    [self.playerShowView pause];

}