iOS 音乐播放器之锁屏效果+歌词解析

旧城等待， 2022-05-31 10:35 237阅读 0赞

# 概述 #

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、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。

# 详细 #

#### 代码下载：[http://www.demodashi.com/demo/10754.html][http_www.demodashi.com_demo_10754.html] ####

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

![1234.gif][]

//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

![1708447-afcb25273e2ea214.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];

![1708447-db2d2d4cc57e27d0.png][]![1708447-7b19e1725fff23e0.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][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

![1708447-285ef497840bff48.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;
                        }
                    }

第三部分：项目截图

![屏幕快照 2017-08-01 下午5.36.21.png][2017-08-01 _5.36.21.png]

#### 代码下载：[http://www.demodashi.com/demo/10754.html][http_www.demodashi.com_demo_10754.html] ####

#### 注：本文著作权归作者，由demo大师发表，拒绝转载，转载需要作者授权 ####

[http_www.demodashi.com_demo_10754.html]: http://www.demodashi.com/demo/10754.html
[1234.gif]: /images/20220531/998c3b83c6e2430692c34187ff938d25.png
[1708447-afcb25273e2ea214.png]: /images/20220531/f495c92f963740d6af72c91be82760e5.png
[1708447-db2d2d4cc57e27d0.png]: http://www.demodashi.com/ueditor/jsp/upload/image/20170731/1501471011065030131.png
[1708447-7b19e1725fff23e0.png]: /images/20220531/d0fd577e68a94336ade8dbc485e66b5d.png
[https_developer.apple.com_documentation_mediaplayer_mpremotecommandcenter]: https://developer.apple.com/documentation/mediaplayer/mpremotecommandcenter
[1708447-285ef497840bff48.png]: /images/20220531/b82f05f4abbb42729999fa92a040b642.png
[2017-08-01 _5.36.21.png]: /images/20220531/692a66dfa8544d82a42c98ec5254ddab.png