iOS音乐播放器（歌词自动滚动）

简单实现基于IOS的音乐播放器，并且带有歌词，随播放自动滚动，实现效果如下：

首先，需要建立一个解析歌词的类ZMPlrc，解析歌词主要就是把时间和对应的歌词分离出来，然后存储到数组中。

ZMPlrc.h

#import <Foundation/Foundation.h>

@interface ZMPlrc : NSObject

/**
 时间
 */
@property (nonatomic,strong)NSMutableArray *timeArray;
/**
 歌词
 */
@property (nonatomic,strong)NSMutableArray *wordArray;

/**
 解析歌词
 */
- (void)parselrc;

@end

ZMPlrc.m

#import "ZMPlrc.h"

@implementation ZMPlrc

- (instancetype)init
{
    self = [super init];
    if (self) {
        _timeArray = [NSMutableArray array];
        _wordArray = [NSMutableArray array];
    }
    return self;
}

/**
 歌词路径
 */
- (NSString *)getLrcPath{
    return [[NSBundle mainBundle] pathForResource:@"梁静茹-偶阵雨" ofType:@"lrc"];
}

/**
 解析歌词
 */
- (void)parselrc{
    NSString *content = [NSString stringWithContentsOfFile:[self getLrcPath] encoding:NSUTF8StringEncoding error:nil];

    NSArray *sepArray = [content componentsSeparatedByString:@"["];
    for (int i = 5; i < sepArray.count; i ++) {
        //有两个元素，一个是时间，一个是歌词
        NSArray *arr = [sepArray[i] componentsSeparatedByString:@"]"];
        //NSLog(@"%@",sepArray[i]);

        [_timeArray addObject:arr[0]];
        [_wordArray addObject:arr[1]];

    }

    //NSLog(@"%@",content);
}

@end

接着，在storyboard中添加必要的控件。

最后，就可以在控制器中实现了ZMPViewController，在实现过程中，主要就是监听音频播放player的播放时间，跟之前解析好的每句歌词对应的时间进行处理。

ZMPViewController.h

#import <UIKit/UIKit.h>

@interface ZMPViewController : UIViewController
@property (weak, nonatomic) IBOutlet UITableView *lrcTableView;
@property (weak, nonatomic) IBOutlet UISlider *timeSlider;
@property (weak, nonatomic) IBOutlet UILabel *currentTimeLabel;

@property (weak, nonatomic) IBOutlet UILabel *totalTimeLabel;

@property (weak, nonatomic) IBOutlet UIButton *lastMusicBtnClick;
- (IBAction)playBtnClick:(UIButton *)sender;
- (IBAction)preMusicBtnClick:(id)sender;
- (IBAction)valueChange:(UISlider *)sender;

- (IBAction)nextMusicBtnClick:(id)sender;
@end

ZMPViewController.m

#import "ZMPViewController.h"
#import <AVFoundation/AVFoundation.h>
#import "ZMPlrc.h"

@interface ZMPViewController ()<UITableViewDataSource,UITableViewDelegate>{
    //音乐播放器
    AVAudioPlayer *player;

    ZMPlrc *lrc;

    NSInteger currentRow;
}

@end

@implementation ZMPViewController

- (void)viewDidLoad
{
    [super viewDidLoad];
	// Do any additional setup after loading the view, typically from a nib.

    [self initPlayer];

    //侦听当前时间
    [NSTimer scheduledTimerWithTimeInterval:0.5 target:self selector:@selector(updateTime) userInfo:nil repeats:YES];

    lrc = [[ZMPlrc alloc] init];
    [lrc parselrc];

    [self.lrcTableView registerClass:[UITableViewCell class] forCellReuseIdentifier:@"CELL"];
    [self.lrcTableView reloadData];

}

- (void)updateTime{
    CGFloat currentTime = player.currentTime;

    //
    self.currentTimeLabel.text = [NSString stringWithFormat:@"%02d:%02d",(int)currentTime / 60, (int)currentTime % 60];
    self.timeSlider.value = currentTime / player.duration;

    for (int i = 0; i < lrc.timeArray.count; i ++) {

        NSArray *arr = [lrc.timeArray[i] componentsSeparatedByString:@":"];

        CGFloat compTime = [arr[0] integerValue]*60 + [arr[1] floatValue];

        if (player.currentTime > compTime)
        {
            currentRow = i;
        }
        else
        {
            break;
        }
    }

    [self.lrcTableView reloadData];
    [self.lrcTableView scrollToRowAtIndexPath:[NSIndexPath indexPathForRow:currentRow inSection:0] atScrollPosition:UITableViewScrollPositionMiddle animated:YES];
}

/**
 初始化音乐播放器
 */
- (void)initPlayer{

    //后台播放音频设置
    AVAudioSession *session = [AVAudioSession sharedInstance];
    [session setActive:YES error:nil];
    [session setCategory:AVAudioSessionCategoryPlayback error:nil];

    //让app支持接受远程控制事件
    [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];

    NSString *path = [[NSBundle mainBundle] pathForResource:@"梁静茹-偶阵雨" ofType:@"mp3"];
    NSURL *url = [NSURL fileURLWithPath:path];

    player = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:nil];

    //声道 -1------左声道，1-----右声道
    player.pan = 0;

    //音量:0~1
    player.volume = 1;

    //单曲循环(负数表示单曲循环)
    player.numberOfLoops = -1;

    //速率（默认为1）
    //player.enableRate = YES;
    //player.rate = 1.0;

    //总时间
    CGFloat totalSeconds = player.duration;
    self.totalTimeLabel.text = [NSString stringWithFormat:@"%02d:%02d",(int)totalSeconds / 60, (int)totalSeconds % 60];

    //当前时间
    player.currentTime;

#if 0
    //播放
    [player play];

    //停止
    [player stop];

    //暂停
    [player pause];

#endif

}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (IBAction)playBtnClick:(UIButton *)sender {

    sender.selected = !sender.selected;
    if (sender.selected) {
        [player prepareToPlay];
        [player play];
    }else{
        [player pause];
    }
}

- (IBAction)preMusicBtnClick:(id)sender {
    [self initPlayer];
}

- (IBAction)valueChange:(UISlider *)sender {
       player.currentTime = player.duration * sender.value;
}

- (IBAction)nextMusicBtnClick:(id)sender {
    [self initPlayer];
}

#pragma mark - TableViewDelegate
- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section{
    return lrc.wordArray.count;
}
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"CELL"];

    if (indexPath.row == currentRow)
    {
        cell.textLabel.textColor = [UIColor redColor];
    }
    else
    {
        cell.textLabel.textColor = [UIColor blackColor];
    }

    cell.textLabel.textAlignment = NSTextAlignmentCenter;

    cell.textLabel.font = [UIFont systemFontOfSize:15];

    cell.textLabel.text = lrc.wordArray[indexPath.row];

    return cell;
}

@end

需要音乐在程序进入后台后同样能够播放，那么在plist文件中，增加Required background modes设置item 0的value为App plays audio or streams audio/video using AirPlay

并在控制器中，添加后台播放音频的设置

    //后台播放音频设置
    AVAudioSession *session = [AVAudioSession sharedInstance];
    [session setActive:YES error:nil];
    [session setCategory:AVAudioSessionCategoryPlayback error:nil];

    //让app支持接受远程控制事件
    [[UIApplication sharedApplication] beginReceivingRemoteControlEvents];

另外，需要Demo的可以留言。