簡介

• AVAudioPlayer音訊播放器可以提供簡單的音訊播放功能，其標頭檔案包含在AVFoudation.framework中。

• AVAudioPlayer未提供視覺化介面，需要通過其提供的播放控制介面自行實現。

• AVAudioPlayer僅能播放本地音訊檔案，並支援以下格式檔案：.mp3、.m4a、.wav、.caf、.aif
。

常用方法

• 初始化方法

// 1、NSURL 它只能從file://格式的URL裝入音訊資料，不支援流式音訊及HTTP流和網路流。
- (id)initWithContentsOfURL:(NSURL *)url error:(NSError **)outError;

// 2、它使用一個指向記憶體中一些音訊資料的NSData物件，這種形式對於已經把音訊資料下載到緩衝區的情形很有用。
 

- (id)initWithData:(NSData *)data error:(NSError **)outError;

• 音訊操作方法

1、將音訊資源加入音訊佇列，準備播放
- (BOOL)prepareToPlay;

2、開始播放音樂
- (BOOL)play;

3、在指定的延遲時間後開始播放
- (BOOL)playAtTime:(NSTimeInterval)time

4、暫停播放
- (void)pause;

5、停止播放
- (void)stop;           

常用屬性

• playing：檢視播放器是否處於播放狀態

• duration：獲取音訊播放總時長

• delegate：設定委託

• currentTime：設定播放當前時間

• numberOfLoops：設定播放迴圈

• pan：設定聲道

• rate：設定播放速度

AVAudioPlayerDelegate

• AVAudioPlayerDelegate委託協議包含了大量的播放狀態協議方法，來對播放的不同狀態事件進行自定義處理：

// 1、完成播放 
- (void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag;

// 2、播放失敗
- (void)audioPlayerDecodeErrorDidOccur:(AVAudioPlayer
 
 *)player error:(NSError *)error;

// 3、音訊中斷

// 播放中斷結束後，比如突然來的電話造成的中斷 
- (void)audioPlayerEndInterruption:(AVAudioPlayer *)player withOptions:(NSUInteger)flags;

- (void)audioPlayerBeginInterruption:(AVAudioPlayer *)player;

- (void)audioPlayerEndInterruption:(AVAudioPlayer *)player withFlags:(NSUInteger)flags;

- (void)audioPlayerEndInterruption:(AVAudioPlayer *)player;

AVURLAsset獲取專輯資訊

通過AVURLAsset可獲取mp3專輯資訊，包括專輯名稱、專輯圖片、歌曲名、藝術家、專輯縮圖等資訊。

commonKey

• AVMetadataCommonKeyArtist：藝術家

• AVMetadataCommonKeyTitle：音樂名

• AVMetadataCommonKeyArtwork：專輯圖片

• AVMetadataCommonKeyAlbumName：專輯名稱

獲取步驟

steps 1：初始化

// 獲取音訊檔案路徑集合（獲取所有的.mp3格式的檔案路徑）
   NSArray *musicNames = [NSArray arrayWithArray:[[NSBundle mainBundle] pathsForResourcesOfType:@"mp3" inDirectory:nil]];

// 獲取最後一首歌曲（假定獲取最後一首歌曲）的專輯資訊
   NSString *musicName = [musicNames.lastObject lastPathComponent];

// 根據歌曲名稱獲取音訊路徑
   NSString *path = [[NSBundle mainBundle] pathForAuxiliaryExecutable:musicName];

// 根據音訊路徑建立資源地址
   NSURL *url = [NSURL fileURLWithPath:path];

// 初始化AVURLAsset
   AVURLAsset *mp3Asset = [AVURLAsset URLAssetWithURL:url];

steps 2：遍歷獲取資訊

// 遍歷有效元資料格式
    for (NSString *format in [mp3Asset availableMetadataFormats]) {

        // 根據資料格式獲取AVMetadataItem（資料成員）；
        // 根據AVMetadataItem屬性commonKey能夠獲取專輯資訊；
        for (AVMetadataItem *metadataItem in [mp3Asset metadataForFormat:format]) {
            // NSLog(@"%@", metadataItem);

            // 1、獲取藝術家（歌手）名字commonKey：AVMetadataCommonKeyArtist
            if ([metadataItem.commonKey isEqual:AVMetadataCommonKeyArtist]) {
                NSLog(@"%@", (NSString *)metadataItem.value);
            }
            // 2、獲取音樂名字commonKey：AVMetadataCommonKeyTitle
            else if ([metadataItem.commonKey isEqual:AVMetadataCommonKeyTitle]) {
                NSLog(@"%@", (NSString *)metadataItem.value);
            }
            // 3、獲取專輯圖片commonKey：AVMetadataCommonKeyArtwork
            else if ([metadataItem.commonKey isEqual:AVMetadataCommonKeyArtwork]) {
                NSLog(@"%@", (NSData *)metadataItem.value);
            }
            // 4、獲取專輯名commonKey：AVMetadataCommonKeyAlbumName
            else if ([metadataItem.commonKey isEqual:AVMetadataCommonKeyAlbumName]) {
                NSLog(@"%@", (NSString *)metadataItem.value);
            }
        }
    }

音訊播放器案例

案例主要實現：播放、暫停、上一曲、下一曲、拖動滑條改變音量、拖動滑條改變當前進度、播放當前時間以及剩餘時間顯示、通過AVURLAsset類獲取音訊的專輯資訊（包括專輯圖片、歌手、歌曲名等）。

素材下載

效果展示

程式碼示例

上述展示效果中，歌曲名稱實際上是導航欄標題，我只是將導航欄背景顏色設定成黑色，標題顏色以及狀態列顏色設定成白色。新增導航欄、導航欄配置以及修改狀態列顏色，這裡省略，下面直接貼上實現程式碼。

#import <UIKit/UIKit.h>

@interface ViewController : UIViewController

@end

#import "ViewController.h"
#import <AVFoundation/AVFoundation.h>

typedef enum : NSUInteger {
    PlayAndPauseBtnTag,
    NextMusicBtnTag,
    LastMusicBtnTag,
} BtnTag;

#define TIME_MINUTES_KEY @"minutes" // 時間_分_鍵
#define TIME_SECONDS_KEY @"seconds" // 時間_秒_鍵

#define RGB_COLOR(_R,_G,_B) [UIColor colorWithRed:_R/255.0 green:_G/255.0 blue:_B/255.0 alpha:1]

@interface ViewController () <AVAudioPlayerDelegate>

{
    NSTimer *_timer; /**< 定時器 */

    BOOL _playing; /**< 播放狀態 */
    BOOL _shouldUpdateProgress; /**< 是否更新進度指示器 */

    NSArray *_musicNames; /**< 音樂名集合 */

    NSInteger _currentMusicPlayIndex; /**< 當前音樂播放下標 */
}

@property (nonatomic, strong) UILabel     *singerLabel;/**< 歌手 */
@property (nonatomic, strong) UIImageView *imageView;/**< 專輯圖片 */
@property (nonatomic, strong) UIImageView *volumeImageView; /**< 音量圖片 */



@property (nonatomic, strong) UISlider *slider;/**< 進度指示器 */
@property (nonatomic, strong) UISlider *volumeSlider;/**< 音量滑條 */


@property (nonatomic, strong) UIButton *playAndPauseBtn; /**< 暫停播放按鈕 */
@property (nonatomic, strong) UIButton *nextMusicBtn; /**< 下一曲按鈕 */
@property (nonatomic, strong) UIButton *lastMusicBtn; /**< 上一曲按鈕 */

@property (nonatomic, strong) UILabel *currentTimeLabel; /**< 當前時間 */
@property (nonatomic, strong) UILabel *remainTimeLabel;  /**< 剩餘時間 */

@property (nonatomic, strong) AVAudioPlayer *audioPlayer; /**< 音訊播放器 */


// 初始化
- (void)initializeDataSource; /**< 初始化資料來源 */
- (void)initializeUserInterface; /**< 初始化使用者介面 */
- (void)initializeAudioPlayerWithMusicName:(NSString *)musicName shouleAutoPlay:(BOOL)autoPlay; /**< 初始化音訊播放器 */

// 更新
- (void)updateSlider; /**< 重新整理滑條 */
- (void)updateUserInterface; /**< 重新整理使用者介面 */
- (void)updateTimeDisplayWithDuration:(NSTimeInterval)duration currentTime:(NSTimeInterval)currentTime; /**< 更新時間顯示 */

// 定時器
- (void)startTimer; /**< 啟動定時器 */
- (void)pauseTimer; /**< 暫停定時器 */
- (void)stopTimer;  /**< 停止定時器 */

// 事件方法
- (void)respondsToButton:(UIButton *)sender; /**< 點選按鈕 */

- (void)respondsToSliderEventValueChanged:(UISlider *)sender; /**< 拖動滑條 */
- (void)respondsToSliderEventTouchDown:(UISlider *)sender; /**< 按下滑條 */
- (void)respondsToSliderEventTouchUpInside:(UISlider *)sender; /**< 滑條按下擡起 */
- (void)respondsToVolumeSlider:(UISlider *)sender; /**< 拖動音量滑條 */

// 其他方法
- (NSDictionary *)handleWithTime:(NSTimeInterval)time; /**< 處理時間 */


@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    [self initializeDataSource];
    [self initializeUserInterface];
}

#pragma mark *** Initialize methods ***
- (void)initializeDataSource {

    // 賦值是否播放，初始化音訊播放器時，不播放音樂
    _playing = NO;

    // 賦值是否重新整理進度指示
    _shouldUpdateProgress = YES;

    // 設定當前播放音樂下標
    _currentMusicPlayIndex = 0;

    // 獲取bundle路徑所有的mp3格式檔案集合
    _musicNames = [NSArray arrayWithArray:[[NSBundle mainBundle] pathsForResourcesOfType:@"mp3" inDirectory:nil]];

    [_musicNames enumerateObjectsUsingBlock:^(NSString *  _Nonnull musicName, NSUInteger idx, BOOL * _Nonnull stop) {
        NSLog(@"%@", musicName.lastPathComponent);
    }];

}

- (void)initializeUserInterface {

    self.view.backgroundColor = [UIColor blackColor];
    self.navigationController.navigationBar.barTintColor = [UIColor blackColor];
    self.navigationController.navigationBar.tintColor = [UIColor whiteColor];
    self.navigationController.navigationBar.titleTextAttributes = @{NSFontAttributeName:[UIFont boldSystemFontOfSize:25],
                                                                    NSForegroundColorAttributeName:[UIColor whiteColor]};

    // 載入檢視
    [self.view addSubview:self.singerLabel];
    [self.view addSubview:self.imageView];
    [self.view addSubview:self.slider];

    [self.view addSubview:self.playAndPauseBtn];
    [self.view addSubview:self.nextMusicBtn];
    [self.view addSubview:self.lastMusicBtn];

    [self.view addSubview:self.currentTimeLabel];
    [self.view addSubview:self.remainTimeLabel];

    [self.view addSubview:self.volumeSlider];
    [self.view addSubview:self.volumeImageView];

    // 初始化音樂播放器
    [self initializeAudioPlayerWithMusicName:_musicNames[_currentMusicPlayIndex] shouleAutoPlay:_playing];
}

- (void)initializeAudioPlayerWithMusicName:(NSString *)musicName shouleAutoPlay:(BOOL)autoPlay {
    // 異常處理
    if (musicName.length == 0) {
        return;
    }

    NSError *error = nil;

    // 獲取音訊地址
    NSURL *url = [[NSBundle mainBundle] URLForAuxiliaryExecutable:musicName];

    // 初始化音訊播放器
    self.audioPlayer = [[AVAudioPlayer alloc] initWithContentsOfURL:url error:&error];

    // 設定代理
    self.audioPlayer.delegate = self;

    // 判斷是否異常
    if (error) {
        // 列印異常描述資訊
        NSLog(@"%@", error.localizedDescription);
    }else {

        // 設定音量
        self.audioPlayer.volume = self.volumeSlider.value;

        // 準備播放
        [self.audioPlayer prepareToPlay];

        // 播放持續時間
        NSLog(@"音樂持續時間：%.2f", self.audioPlayer.duration);

        if (autoPlay) {
            [self.audioPlayer play];
        }
    }

    // 更新使用者介面
    [self updateUserInterface];
}

#pragma mark *** Timer ***
- (void)startTimer {
    if (!_timer) {
        _timer = [NSTimer scheduledTimerWithTimeInterval:1.0 target:self selector:@selector(updateSlider) userInfo:nil repeats:YES];
    }
    _timer.fireDate = [NSDate date];
}

- (void)pauseTimer {
    _timer.fireDate = [NSDate distantFuture];
}

- (void)stopTimer {
    // 銷燬定時器
    if ([_timer isValid]) {
        [_timer invalidate];
    }
}


#pragma mark *** Events ***
- (void)respondsToButton:(UIButton *)sender {
    switch (sender.tag) {
            // 暫停播放
        case PlayAndPauseBtnTag: {
            if (!_playing) {
                [_audioPlayer play];
                [self startTimer];
            }else {
                [_audioPlayer pause];
                [self pauseTimer];
            }
            _playing = !_playing;
            sender.selected = _playing;
        }
            break;
            // 上一曲
        case LastMusicBtnTag: {
            _currentMusicPlayIndex = _currentMusicPlayIndex == 0 ? _musicNames.count - 1 : --_currentMusicPlayIndex;
            [self initializeAudioPlayerWithMusicName:[_musicNames[_currentMusicPlayIndex] lastPathComponent] shouleAutoPlay:_playing];
        }
            break;
            // 下一曲
        case NextMusicBtnTag: {
            _currentMusicPlayIndex = _currentMusicPlayIndex == _musicNames.count - 1 ? 0 : ++_currentMusicPlayIndex;
            [self initializeAudioPlayerWithMusicName:[_musicNames[_currentMusicPlayIndex] lastPathComponent] shouleAutoPlay:_playing];
        }
            break;

        default:
            break;
    }
}

// 拖動滑條更新時間顯示
- (void)respondsToSliderEventValueChanged:(UISlider *)sender {
    [self updateTimeDisplayWithDuration:sender.maximumValue currentTime:sender.value];
}

// 滑條按下時停止更新滑條
- (void)respondsToSliderEventTouchDown:(UISlider *)sender {
    _shouldUpdateProgress = NO;
}

// 滑條按下擡起，更新當前音樂播放時間
- (void)respondsToSliderEventTouchUpInside:(UISlider *)sender {
    _shouldUpdateProgress = YES;
    self.audioPlayer.currentTime = sender.value;
}


- (void)respondsToVolumeSlider:(UISlider *)sender {
    self.audioPlayer.volume = sender.value;
}

#pragma mark *** Update methods ***
- (void)updateSlider {
    // 在拖動滑條的過程中，停止重新整理播放進度
    if (_shouldUpdateProgress) {
        // 更新進度指示
        self.slider.value = self.audioPlayer.currentTime;
        // 更新時間顯示
        [self updateTimeDisplayWithDuration:self.audioPlayer.duration currentTime:self.audioPlayer.currentTime];
    }
}

- (void)updateUserInterface {

    /* 進度指示更新 */
    self.slider.value = 0.0;
    self.slider.minimumValue = 0.0;
    self.slider.maximumValue = self.audioPlayer.duration;

    /* 標題更新 */
    self.title = [_musicNames[_currentMusicPlayIndex] substringToIndex:((NSString *)_musicNames[_currentMusicPlayIndex]).length - 4];

    /* 獲取MP3專輯資訊 */
    // 獲取音樂路徑
    NSString *path = [[NSBundle mainBundle] pathForAuxiliaryExecutable:[_musicNames[_currentMusicPlayIndex] lastPathComponent]];
    // 根據音樂路徑建立url資源地址
    NSURL *url = [NSURL fileURLWithPath:path];
    // 初始化AVURLAsset
    AVURLAsset *map3Asset = [AVURLAsset assetWithURL:url];
    // 遍歷有效元資料格式
    for (NSString *format in [map3Asset availableMetadataFormats]) {
        // 根據資料格式獲取AVMetadataItem資料成員
        for (AVMetadataItem *metadataItem in [map3Asset metadataForFormat:format]) {
            // 獲取專輯圖片commonKey：AVMetadataCommonKeyArtwork
            if ([metadataItem.commonKey isEqualToString:AVMetadataCommonKeyArtwork]) {
                UIImage *image = [UIImage imageWithData:(NSData *)metadataItem.value];
                // 更新專輯圖片
                self.imageView.image = image;
            }
            // 獲取音樂名字commonKey：AVMetadataCommonKeyTitle
            else if([metadataItem.commonKey isEqualToString:AVMetadataCommonKeyTitle]){
                // 更新音樂名稱
                self.title = (NSString *)metadataItem.value;
            }
            // 獲取藝術家（歌手）名字commonKey：AVMetadataCommonKeyArtist
            else if ([metadataItem.commonKey isEqual:AVMetadataCommonKeyArtist]){
                // 更新歌手
                self.singerLabel.text = [NSString stringWithFormat:@"- %@ -", metadataItem.value];
            }
        }
    }
}



- (void)updateTimeDisplayWithDuration:(NSTimeInterval)duration currentTime:(NSTimeInterval)currentTime {
    /* 處理當前時間 */
    NSDictionary *currentTimeInfoDict = [self handleWithTime:currentTime];
    // 取出對應的分秒元件
    NSInteger currentMinutes = [[currentTimeInfoDict objectForKey:TIME_MINUTES_KEY] integerValue];
    NSInteger currentSeconds = [[currentTimeInfoDict objectForKey:TIME_SECONDS_KEY] integerValue];
    // 時間格式處理
    NSString *currentTimeFormat = currentSeconds < 10 ? @"0%d:0%d" : @"0%d:%d";
    NSString *currentTimeString = [NSString stringWithFormat:currentTimeFormat, currentMinutes, currentSeconds];
    self.currentTimeLabel.text = currentTimeString;

    /* 處理剩餘時間 */
    NSDictionary *remainTimeInfoDict = [self handleWithTime:duration - currentTime];
    // 取出對應的過分秒元件
    NSInteger remainMinutes = [[remainTimeInfoDict objectForKey:TIME_MINUTES_KEY] integerValue];
    NSInteger remainSeconds = [[remainTimeInfoDict objectForKey:TIME_SECONDS_KEY] integerValue];
    // 時間格式處理
    NSString *remainTimeFormat = remainSeconds < 10 ? @"0%d:0%d" : @"-0%d:%d";
    NSString *remainTimeString = [NSString stringWithFormat:remainTimeFormat, remainMinutes, remainSeconds];
    self.remainTimeLabel.text = remainTimeString;
}

- (NSDictionary *)handleWithTime:(NSTimeInterval)time {
    NSMutableDictionary *timeInfomationDict = [@{} mutableCopy];
    // 獲取分
    NSInteger minutes = (NSInteger)time/60;
    // 獲取秒
    NSInteger seconds = (NSInteger)time%60;
    // 打包字典
    [timeInfomationDict setObject:@(minutes) forKey:TIME_MINUTES_KEY];
    [timeInfomationDict setObject:@(seconds) forKey:TIME_SECONDS_KEY];
    return timeInfomationDict;
}

#pragma mark *** AVAudioPlayerDelegate ***
- (void)audioPlayerDidFinishPlaying:(AVAudioPlayer *)player successfully:(BOOL)flag {
    [self respondsToButton:self.nextMusicBtn];
}

#pragma mark *** Setters ***
- (void)setAudioPlayer:(AVAudioPlayer *)audioPlayer {
    // 在設定音訊播放器的時候，如果正在播放，則先暫停音樂再進行配置
    if (_audioPlayer.playing) {
        [_audioPlayer stop];
    }
    _audioPlayer = audioPlayer;
}

#pragma mark *** Getters ***
- (UILabel *)singerLabel {
    if (!_singerLabel) {
        _singerLabel = [[UILabel alloc] init];
        _singerLabel.bounds = CGRectMake(0, 0, CGRectGetWidth(self.view.bounds), 40);
        _singerLabel.center = CGPointMake(CGRectGetMidX(self.view.bounds), 64 + CGRectGetMidY(_singerLabel.bounds));
        _singerLabel.textColor = [UIColor whiteColor];
        _singerLabel.font = [UIFont systemFontOfSize:17];
        _singerLabel.textAlignment = NSTextAlignmentCenter;
    }
    return _singerLabel;
}

- (UIImageView *)imageView {
    if (!_imageView) {
        _imageView = [[UIImageView alloc] init];
        _imageView.bounds = CGRectMake(0, 0, CGRectGetWidth(self.view.bounds) - 180, CGRectGetWidth(self.view.bounds) - 180);
        _imageView.center = CGPointMake(CGRectGetMidX(self.view.bounds), CGRectGetMaxY(self.singerLabel.frame) + CGRectGetMidY(_imageView.bounds) + 30);
        _imageView.backgroundColor = [UIColor cyanColor];
        _imageView.layer.cornerRadius = CGRectGetMidX(_imageView.bounds);
        _imageView.layer.masksToBounds = YES;
        _imageView.alpha = 0.85;
    }
    return _imageView;
}

- (UISlider *)slider {
    if (!_slider) {
        _slider = [[UISlider alloc] init];
        _slider.bounds = CGRectMake(0, 0, CGRectGetWidth(self.view.bounds) - 100, 30);
        _slider.center = CGPointMake(CGRectGetMidX(self.view.bounds), CGRectGetMaxY(self.imageView.frame) + CGRectGetMidY(_slider.bounds) + 50);
        _slider.maximumTrackTintColor = [UIColor lightGrayColor];
        _slider.minimumTrackTintColor = RGB_COLOR(30, 177, 74);
        _slider.layer.masksToBounds = YES;

        // 自定義拇指圖片
        [_slider setThumbImage:[UIImage imageNamed:@"iconfont-yuan"] forState:UIControlStateNormal];

        // 事件監聽
        [_slider addTarget:self action:@selector(respondsToSliderEventValueChanged:) forControlEvents:UIControlEventValueChanged];
        [_slider addTarget:self action:@selector(respondsToSliderEventTouchDown:) forControlEvents:UIControlEventTouchDown];
        [_slider addTarget:self action:@selector(respondsToSliderEventTouchUpInside:) forControlEvents:UIControlEventTouchUpInside];


    }
    return _slider;
}

- (UIButton *)playAndPauseBtn {
    if (!_playAndPauseBtn) {
        _playAndPauseBtn = [UIButton buttonWithType:UIButtonTypeCustom];
        _playAndPauseBtn.bounds = CGRectMake(0, 0, 100, 100);
        _playAndPauseBtn.center = CGPointMake(CGRectGetMidX(self.view.bounds), CGRectGetMaxY(self.slider.frame) + CGRectGetMidY(_playAndPauseBtn.bounds) + 30);
        _playAndPauseBtn.tag = PlayAndPauseBtnTag;
        [_playAndPauseBtn setImage:[UIImage imageNamed:@"iconfont-bofang"] forState:UIControlStateNormal];
        [_playAndPauseBtn setImage:[UIImage imageNamed:@"iconfont-zanting"] forState:UIControlStateSelected];
        [_playAndPauseBtn addTarget:self action:@selector(respondsToButton:) forControlEvents:UIControlEventTouchUpInside];
    }
    return _playAndPauseBtn;
}

- (UIButton *)nextMusicBtn {
    if (!_nextMusicBtn) {
        _nextMusicBtn = [UIButton buttonWithType:UIButtonTypeCustom];
        _nextMusicBtn.bounds = CGRectMake(0, 0, 60, 60);
        _nextMusicBtn.center = CGPointMake(CGRectGetMaxX(self.playAndPauseBtn.frame) + CGRectGetMidX(_nextMusicBtn.bounds) + 20, CGRectGetMidY(self.playAndPauseBtn.frame));
        _nextMusicBtn.tag = NextMusicBtnTag;
        [_nextMusicBtn setImage:[UIImage imageNamed:@"iconfont-xiayiqu"] forState:UIControlStateNormal];
        [_nextMusicBtn addTarget:self action:@selector(respondsToButton:) forControlEvents:UIControlEventTouchUpInside];
    }
    return _nextMusicBtn;
}

- (UIButton *)lastMusicBtn {
    if (!_lastMusicBtn) {
        _lastMusicBtn = [UIButton buttonWithType:UIButtonTypeCustom];
        _lastMusicBtn.bounds = CGRectMake(0, 0, 60, 60);
        _lastMusicBtn.center = CGPointMake(CGRectGetMinX(self.playAndPauseBtn.frame) - 20 - CGRectGetMidX(_lastMusicBtn.bounds), CGRectGetMidY(self.playAndPauseBtn.frame));
        _lastMusicBtn.tag = LastMusicBtnTag;
        [_lastMusicBtn setImage:[UIImage imageNamed:@"iconfont-shangyiqu"] forState:UIControlStateNormal];
        [_lastMusicBtn addTarget:self action:@selector(respondsToButton:) forControlEvents:UIControlEventTouchUpInside];
    }
    return _lastMusicBtn;
}

- (UILabel *)currentTimeLabel {
    if (!_currentTimeLabel) {
        _currentTimeLabel = [[UILabel alloc] init];
        _currentTimeLabel.bounds = CGRectMake(0, 0, 50, 30);
        _currentTimeLabel.center = CGPointMake(CGRectGetMidX(_currentTimeLabel.bounds), CGRectGetMidY(self.slider.frame));
        _currentTimeLabel.textAlignment = NSTextAlignmentRight;
        _currentTimeLabel.font = [UIFont systemFontOfSize:14];
        _currentTimeLabel.textColor = [UIColor lightGrayColor];
        _currentTimeLabel.text = @"00:00";
    }
    return _currentTimeLabel;
}

- (UILabel *)remainTimeLabel {
    if (!_remainTimeLabel) {
        _remainTimeLabel = [[UILabel alloc] init];
        _remainTimeLabel.bounds = self.currentTimeLabel.bounds;
        _remainTimeLabel.center = CGPointMake(CGRectGetMaxX(self.slider.frame) + CGRectGetMidX(_remainTimeLabel.bounds), CGRectGetMidY(self.slider.frame));
        _remainTimeLabel.font = [UIFont systemFontOfSize:14];
        _remainTimeLabel.textColor = [UIColor lightGrayColor];
        _remainTimeLabel.text = @"00:00";
    }
    return _remainTimeLabel;
}

- (UIImageView *)volumeImageView {
    if (!_volumeImageView) {
        _volumeImageView = [[UIImageView alloc] init];
        _volumeImageView.bounds = CGRectMake(0, 0, 35, 35);
        _volumeImageView.center = CGPointMake(20 + CGRectGetMidX(_volumeImageView.bounds),  CGRectGetMaxY(self.playAndPauseBtn.frame) + CGRectGetMidY(_volumeImageView.bounds) + 40);
        _volumeImageView.image = [UIImage imageNamed:@"iconfont-yinliang"];
    }
    return _volumeImageView;
}

- (UISlider *)volumeSlider {
    if (!_volumeSlider) {
        _volumeSlider = [[UISlider alloc] init];
        _volumeSlider.bounds = CGRectMake(0, 0, CGRectGetWidth(self.view.bounds) - 2 * CGRectGetMinX(self.volumeImageView.frame) - CGRectGetWidth(self.volumeImageView.bounds), CGRectGetHeight(self.slider.bounds));
        _volumeSlider.center = CGPointMake(CGRectGetMaxX(self.volumeImageView.frame) + CGRectGetMidX(_volumeSlider.bounds), CGRectGetMidY(self.volumeImageView.frame));
        _volumeSlider.maximumTrackTintColor = [UIColor lightGrayColor];
        _volumeSlider.minimumTrackTintColor = RGB_COLOR(30, 177, 74);
        _volumeSlider.minimumValue = 0.0;
        _volumeSlider.maximumValue = 1.0;
        _volumeSlider.value = 0.5;
        [_volumeSlider setThumbImage:[UIImage imageNamed:@"iconfont-yuan"] forState:UIControlStateNormal];
        [_volumeSlider addTarget:self action:@selector(respondsToVolumeSlider:) forControlEvents:UIControlEventValueChanged];
    }
    return _volumeSlider;
}
@end