iOS 音乐播放器之锁屏歌词+歌词解析+锁屏效果

功能描述：锁屏歌曲信息、控制台远程控制音乐播放：暂停/播放、上一首/下一首、快进/快退、锁屏状态下列表菜单弹框和拖拽控制台的进度条调节进度（结合了QQ音乐和网易云音乐在锁屏状态下的效果）、歌词解析并随音乐滚动显示。

总效果预览图.gif

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第一部分：锁屏效果包括：锁屏歌曲信息和远程控制音乐播放

① 锁屏歌曲信息显示

iOS11以下锁屏信息预览

//展示锁屏歌曲信息：图片、歌词、进度、歌曲名、演唱者、专辑、（歌词是绘制在图片上的）
- (void)showLockScreenTotaltime:(float)totalTime andCurrentTime:(float)currentTime andLyricsPoster:(BOOL)isShow{

    NSMutableDictionary * songDict = [[NSMutableDictionary alloc] init];
    //设置歌曲题目
    [songDict setObject:@"多幸运" forKey:MPMediaItemPropertyTitle];
    //设置歌手名
    [songDict setObject:@"韩安旭" forKey:MPMediaItemPropertyArtist];
    //设置专辑名
    [songDict setObject:@"专辑名" forKey:MPMediaItemPropertyAlbumTitle];
    //设置歌曲时长
    [songDict setObject:[NSNumber numberWithDouble:totalTime]  forKey:MPMediaItemPropertyPlaybackDuration];
    //设置已经播放时长
    [songDict setObject:[NSNumber numberWithDouble:currentTime] forKey:MPNowPlayingInfoPropertyElapsedPlaybackTime];

    UIImage * lrcImage = [UIImage imageNamed:@"backgroundImage5.jpg"];
    if (isShow) {

        //制作带歌词的海报
        if (!_lrcImageView) {
            _lrcImageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 480,800)];
        }
        if (!_lockScreenTableView) {
            _lockScreenTableView = [[UITableView alloc] initWithFrame:CGRectMake(0, 800 - 44 * 7 + 20, 480, 44 * 3) style:UITableViewStyleGrouped];
            _lockScreenTableView.dataSource = self;
            _lockScreenTableView.delegate = self;
            _lockScreenTableView.separatorStyle = NO;
            _lockScreenTableView.backgroundColor = [UIColor clearColor];
            [_lockScreenTableView registerClass:[UITableViewCell class] forCellReuseIdentifier:@"cellID"];
        }
        //主要为了把歌词绘制到图片上，已达到更新歌词的目的
        [_lrcImageView addSubview:self.lockScreenTableView];
        _lrcImageView.image = lrcImage;
        _lrcImageView.backgroundColor = [UIColor blackColor];

        //获取添加了歌词数据的海报图片
        UIGraphicsBeginImageContextWithOptions(_lrcImageView.frame.size, NO, 0.0);
        CGContextRef context = UIGraphicsGetCurrentContext();
        [_lrcImageView.layer renderInContext:context];
        lrcImage = UIGraphicsGetImageFromCurrentImageContext();
        _lastImage = lrcImage;
        UIGraphicsEndImageContext();

    }else{
        if (_lastImage) {
            lrcImage = _lastImage;
        }
    }
    //设置显示的海报图片
    [songDict setObject:[[MPMediaItemArtwork alloc] initWithImage:lrcImage]
                 forKey:MPMediaItemPropertyArtwork];
   //加入正在播放媒体的信息中心
    [[MPNowPlayingInfoCenter defaultCenter] setNowPlayingInfo:songDict];

}

---

② 远程控制音乐播放

左侧列表菜单弹出框.PNG

在此之前需先满足后台播放音乐的条件:

//后台播放音频设置,需要在Capabilities->Background Modes中勾选Audio,Airplay,and Picture in Picture ，如下图1、2
    AVAudioSession *session = [AVAudioSession sharedInstance];
    [session setActive:YES error:nil];
    [session setCategory:AVAudioSessionCategoryPlayback error:nil];

1.png

2.png

• 在iOS7.1之前, App如果需要在锁屏界面开启和监控远程控制事件,可以通过重写- (void)remoteControlReceivedWithEvent:(UIEvent *)event这个方法来捕获远程控制事件，并根据event.subtype来判别指令意图并作出反应。具体用法如下：

//在具体的控制器或其它类中捕获处理远程控制事件,当远程控制事件发生时触发该方法, 该方法属于UIResponder类，iOS 7.1 之前经常用
- (void)remoteControlReceivedWithEvent:(UIEvent *)event{
    NSLog(@"%ld",event.type);
    [[NSNotificationCenter defaultCenter] postNotificationName:@"songRemoteControlNotification" object:self userInfo:@{@"eventSubtype":@(event.subtype)}];
}

 /* iOS 7.1之前*/
     //让App开始接收远程控制事件, 该方法属于UIApplication类
     [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];
     //结束远程控制,需要的时候关闭
     //     [[UIApplication sharedApplication] endReceivingRemoteControlEvents];
     //处理控制台的暂停/播放、上/下一首事件
     [[NSNotificationCenter defaultCenter] addObserverForName:@"songRemoteControlNotification" object:nil queue:[NSOperationQueue mainQueue] usingBlock:^(NSNotification *notification) {

     NSInteger  eventSubtype = [notification.userInfo[@"eventSubtype"] integerValue];
     switch (eventSubtype) {
     case UIEventSubtypeRemoteControlNextTrack:
     NSLog(@"下一首");
     break;
     case UIEventSubtypeRemoteControlPreviousTrack:
     NSLog(@"上一首");
     break;
     case  UIEventSubtypeRemoteControlPause:
     [self.player pause];
     break;
     case  UIEventSubtypeRemoteControlPlay:
     [self.player play];
     break;
     //耳机上的播放暂停
     case  UIEventSubtypeRemoteControlTogglePlayPause:
     NSLog(@"播放或暂停");
     break;
     //后退
     case UIEventSubtypeRemoteControlBeginSeekingBackward:
     break;
     case UIEventSubtypeRemoteControlEndSeekingBackward:
     NSLog(@"后退");
     break;
     //快进
     case UIEventSubtypeRemoteControlBeginSeekingForward:
     break;
     case UIEventSubtypeRemoteControlEndSeekingForward:
     NSLog(@"前进");
     break;
     default:
     break;
     }

     }];

• 在iOS7.1之后，出现了MPRemoteCommandCenter、MPRemoteCommand 及其相关的一些类 ，锁屏界面开启和监控远程控制事件就更方便了，而且还扩展了一些新功能：网易云音乐的列表菜单弹框功能和QQ音乐的拖拽控制台的进度条调节进度功能等等…..
  官方文档：https://developer.apple.com/documentation/mediaplayer/mpremotecommandcenter

//锁屏界面开启和监控远程控制事件
- (void)createRemoteCommandCenter{
    /**/
    //远程控制命令中心 iOS 7.1 之后  详情看官方文档：https://developer.apple.com/documentation/mediaplayer/mpremotecommandcenter

    MPRemoteCommandCenter *commandCenter = [MPRemoteCommandCenter sharedCommandCenter];

    //   MPFeedbackCommand对象反映了当前App所播放的反馈状态. MPRemoteCommandCenter对象提供feedback对象用于对媒体文件进行喜欢, 不喜欢, 标记的操作. 效果类似于网易云音乐锁屏时的效果

    //添加喜欢按钮
    MPFeedbackCommand *likeCommand = commandCenter.likeCommand;
    likeCommand.enabled = YES;
    likeCommand.localizedTitle = @"喜欢";
    [likeCommand addTargetWithHandler:^MPRemoteCommandHandlerStatus(MPRemoteCommandEvent * _Nonnull event) {
        NSLog(@"喜欢");
        return MPRemoteCommandHandlerStatusSuccess;
    }];
    //添加不喜欢按钮，假装是“上一首”
    MPFeedbackCommand *dislikeCommand = commandCenter.dislikeCommand;
    dislikeCommand.enabled = YES;
    dislikeCommand.localizedTitle = @"上一首";
    [dislikeCommand addTargetWithHandler:^MPRemoteCommandHandlerStatus(MPRemoteCommandEvent * _Nonnull event) {
        NSLog(@"上一首");
        return MPRemoteCommandHandlerStatusSuccess;
    }];
    //标记
    MPFeedbackCommand *bookmarkCommand = commandCenter.bookmarkCommand;
    bookmarkCommand.enabled = YES;
    bookmarkCommand.localizedTitle = @"标记";
    [bookmarkCommand addTargetWithHandler:^MPRemoteCommandHandlerStatus(MPRemoteCommandEvent * _Nonnull event) {
        NSLog(@"标记");
        return MPRemoteCommandHandlerStatusSuccess;
    }];

//    commandCenter.togglePlayPauseCommand 耳机线控的暂停/播放

    [commandCenter.pauseCommand addTargetWithHandler:^MPRemoteCommandHandlerStatus(MPRemoteCommandEvent * _Nonnull event) {
        [self.player pause];
        return MPRemoteCommandHandlerStatusSuccess;
    }];
    [commandCenter.playCommand addTargetWithHandler:^MPRemoteCommandHandlerStatus(MPRemoteCommandEvent * _Nonnull event) {
        [self.player play];
        return MPRemoteCommandHandlerStatusSuccess;
    }];
    //    [commandCenter.previousTrackCommand addTargetWithHandler:^MPRemoteCommandHandlerStatus(MPRemoteCommandEvent * _Nonnull event) {
    //        NSLog(@"上一首");
    //        return MPRemoteCommandHandlerStatusSuccess;
    //    }];

    [commandCenter.nextTrackCommand addTargetWithHandler:^MPRemoteCommandHandlerStatus(MPRemoteCommandEvent * _Nonnull event) {
        NSLog(@"下一首");
        return MPRemoteCommandHandlerStatusSuccess;
    }];

    //快进
    //    MPSkipIntervalCommand *skipBackwardIntervalCommand = commandCenter.skipForwardCommand;
    //    skipBackwardIntervalCommand.preferredIntervals = @[@(54)];
    //    skipBackwardIntervalCommand.enabled = YES;
    //    [skipBackwardIntervalCommand addTarget:self action:@selector(skipBackwardEvent:)];

    //在控制台拖动进度条调节进度（仿QQ音乐的效果）
    [commandCenter.changePlaybackPositionCommand addTargetWithHandler:^MPRemoteCommandHandlerStatus(MPRemoteCommandEvent * _Nonnull event) {
        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) {
        }];
        return MPRemoteCommandHandlerStatusSuccess;
    }];


}

-(void)skipBackwardEvent: (MPSkipIntervalCommandEvent *)skipEvent
{
    NSLog(@"快进了 %f秒", skipEvent.interval);
}

第二部分：歌词解析

歌词样式.png

• 根据上图的歌词样式，思路就是：先根据换行符“\n“分割字符串，获得包含每一行歌词字符串的数组，然后解析每一行歌词字符，获得时间点和对应的歌词，再用创建的歌词对象wslLrcEach来存储时间点和歌词，最后得到一个存储wslLrcEach对象的数组。

//每句歌词对象 
@interface wslLrcEach : NSObject 
@property(nonatomic, assign) NSUInteger time ; 
@property(nonatomic, copy) NSString * lrc ; 
@end

接下来就是要让歌词随歌曲的进度来滚动显示,主要代码如下：

self.tableView  显示歌词的
    currentTime  当前播放时间点
    self.currentRow  当前时间点歌词的位置

     //歌词滚动显示
        for ( int i = (int)(self.lrcArray.count - 1); i >= 0 ;i--) {
            wslLrcEach * lrc = self.lrcArray[i];
            if (lrc.time < currentTime) {
                self.currentRow = i;
                [self.tableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow: self.currentRow inSection:0] atScrollPosition:UITableViewScrollPositionMiddle animated:YES];
                [self.tableView reloadData];
                break;
            }
        }

传送门~

iOS11锁屏界面.PNG