iOS mp3播放锁屏界面展示和耳机拔出事件

要实现后台播放的功能，在

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions 方法添加如下代码

//在静音模式下也能播放音频 进入后台也能播放
    // 1.获取音频会话
    AVAudioSession *audioSession = [AVAudioSession sharedInstance];
    // 2.设置后台播放类别
    [audioSession setCategory:AVAudioSessionCategoryPlayback error:nil];
    // 3.激活会话
    [audioSession setActive:YES error:nil];
    // 4.注册响应后台控制
    [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
    [self becomeFirstResponder];

在播放界面添加代码：

这样就能在锁屏时控制音乐播放了

//开启锁屏处理多媒体事件
    [self configRemoteControlEvents];

- (void)configRemoteControlEvents
{
    //初始化远程控制中心
    MPRemoteCommandCenter *commandCenter = [MPRemoteCommandCenter sharedCommandCenter];

    if (@available(iOS 9.1, *)) {

        //暂停
        [commandCenter.pauseCommand addTargetWithHandler:^MPRemoteCommandHandlerStatus(MPRemoteCommandEvent * _Nonnull event) {
            
            self.isPlay = !self.isPlay;

            [self.palyerBtn setImage:[[UIImage imageNamed:@"bg.music.bofang.png"]imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal] forState:UIControlStateNormal];
            [self.player pause];
            [self.musicTimer setFireDate:[NSDate distantFuture]];
            NSLog(@"远程 暂停%@",self.player);
            
            return MPRemoteCommandHandlerStatusSuccess;
        }];
        
        //播放
        [commandCenter.playCommand addTargetWithHandler:^MPRemoteCommandHandlerStatus(MPRemoteCommandEvent * _Nonnull event) {
            
            self.isPlay = !self.isPlay;

            [self.palyerBtn setImage:[[UIImage imageNamed:@"bg.music.zanting.png"]imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal] forState:UIControlStateNormal];
            [self.player play];
            [self.musicTimer setFireDate:[NSDate distantPast]];
            NSLog(@"远程 播放%@",self.player);
            
            return MPRemoteCommandHandlerStatusSuccess;
        }];
        
        
        //下一首
        [commandCenter.nextTrackCommand addTargetWithHandler:^MPRemoteCommandHandlerStatus(MPRemoteCommandEvent * _Nonnull event) {
            
            if (self.musicSlider.value<0.9) {
                //1.slider的value值发生变化时，currentTime也在发生变化（在playerAction中定义了value的公式）
                float current = self.musicSlider.value;
                [self.musicSlider setValue:(current + 0.1) animated:YES];
                //2.获取最终的currentTime
                float nextCurrent = (current + 0.1) * CMTimeGetSeconds(self.player.currentItem.duration);
                //3.拖动slider导致value的值改变时，player能够让正在进行的item追着时间走
                [self.player seekToTime:CMTimeMakeWithSeconds(nextCurrent, 1.0)];
            }
            
            return MPRemoteCommandHandlerStatusSuccess;
        }];
        
        
        //上一首
        [commandCenter.previousTrackCommand addTargetWithHandler:^MPRemoteCommandHandlerStatus(MPRemoteCommandEvent * _Nonnull event) {
            
            if (self.musicSlider.value>0) {
                //1.slider的value值发生变化时，currentTime也在发生变化（在playerAction中定义了value的公式）
                float current = self.musicSlider.value;
                [self.musicSlider setValue:(current - 0.1) animated:YES];
                //2.获取最终的currentTime
                float nextCurrent = (current - 0.1) * CMTimeGetSeconds(self.player.currentItem.duration);
                //3.拖动slider导致value的值改变时，player能够让正在进行的item追着时间走
                [self.player seekToTime:CMTimeMakeWithSeconds(nextCurrent, 1.0)];
            }
            
            return MPRemoteCommandHandlerStatusSuccess;
        }];
        
        
        //进度条拖动
        [commandCenter.changePlaybackPositionCommand addTargetWithHandler:^MPRemoteCommandHandlerStatus(MPRemoteCommandEvent * _Nonnull event) {
            
            //CGFloat seekTime = event.timestamp;
            
            CMTime totlaTime = self.player.currentItem.duration;

            MPChangePlaybackPositionCommandEvent * playbackPositionEvent = (MPChangePlaybackPositionCommandEvent *)event;

            [self.player seekToTime:CMTimeMake(totlaTime.value*playbackPositionEvent.positionTime/CMTimeGetSeconds(totlaTime), totlaTime.timescale) completionHandler:^(BOOL finished) {
                
                //NSLog(@"finished ===> %d",finished);
            }];

            return MPRemoteCommandHandlerStatusSuccess;

            //链接：https://www.jianshu.com/p/f7651c504cd9

        }];
    } else {
        // Fallback on earlier versions
    }

}

 以上仅是部分代码截取记录，仅当参考