iOS基础:AVPlayer的入门以及应用(自定义播放管理器的开发)

一、闲谈

一直用着网易云音乐这个app,也一直想要模拟着它做一个却总是懒得迈出第一步,最近终于下定决心,打算先做一点最基础的。一个音乐播放器最基础的当然就是播放管理器了。

二、AVPlayer的入门

其实AVPlayer用起来很简单,我也就不说废话,直接放上代码。

第一步:初始化等操作

// 初始化一个AVPlayer
self.player = [[AVPlayer alloc] init];
// 创建一个item
AVPlayerItem *item =[AVPlayerItem playerItemWithURL:[NSURL URLWithString:@"http://m2.music.126.net/lpeVipLJshTxA-T7xjFI2g==/1046735069650768.mp3"]];
// 监听status属性
[item addObserver:self forKeyPath:@"status" options:NSKeyValueObservingOptionNew context:nil];
// 监听loadedTimeRanges属性
[item addObserver:self forKeyPath:@"loadedTimeRanges" options:NSKeyValueObservingOptionNew context:nil];
// 设置player的item
[self.player replaceCurrentItemWithPlayerItem:item];

下面再补充一下监听的两个属性。

1.status

这个属性指的是item的状态,状态一共有三种,如下:

typedef NS_ENUM(NSInteger, AVPlayerItemStatus) {
    AVPlayerItemStatusUnknown,
    AVPlayerItemStatusReadyToPlay,
    AVPlayerItemStatusFailed
};

显然,当status为AVPlayerItemStatusReadyToPlay的时候,就说明可以播放了。

2.loadedTimeRanges

这个属性主要是用在获取缓冲的进度的,具体的使用在下文会说到。

第二步:响应监听

既然有监听,那就肯定要响应。先上代码:

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
    if ([keyPath isEqualToString:@"status"]) {
        AVPlayerItemStatus status =[change[@"new"]integerValue];//change为string类型
        switch (status) {
            case AVPlayerItemStatusUnknown:
                NSLog(@"AVPlayerItemStatusUnknown");
                break;          
            case AVPlayerItemStatusReadyToPlay:
                //调用播放方法
                [self.player play];
                break;
            case AVPlayerItemStatusFailed:{
                NSLog(@"AVPlayerItemStatusFailed");
                break;
            }          
            default:
                break;
        }
    } else if ([keyPath isEqualToString:@"loadedTimeRanges"]) {
        // 计算缓冲的进度百分比
        float timeInterval= [self availableDuration];
        NSInteger totalDuration = [self fetchTotalTime];
        // 打印缓冲进度的百分比
        NSLog(@"进度百分比%f", timeInterval / totalDuration);
    }
}

其中监听item的状态的代码就不需要说了,只需要在AVPlayerItemStatusReadyToPlay后加上

[self.player play];

就可以了。
下面讲一下计算缓冲的进度百分比的思路,其实也很简单,先获取到缓冲的进度,再获取到总的时间,然后 缓冲的进度/总时间 就是缓冲的百分比。

自己写一个获取总时间的方法:
// 获取总时间,总秒数
- (NSInteger)fetchTotalTime
{
    //获取当前播放歌曲的总时间
    CMTime time = self.player.currentItem.duration;
    
    if (time.timescale == 0) {
        return 0;
    }
    //播放秒数 = time.value/time.timescale
    return time.value/time.timescale;
}
自己写一个获取缓冲总进度的方法:
- (float)availableDuration
{
    NSArray *loadedTimeRanges = [[self.player currentItem] loadedTimeRanges];
    CMTimeRange timeRange = [loadedTimeRanges.firstObject CMTimeRangeValue];// 获取缓冲区域
    float startSeconds = CMTimeGetSeconds(timeRange.start);
    float durationSeconds = CMTimeGetSeconds(timeRange.duration);
    float result = startSeconds + durationSeconds;// 计算缓冲总进度
    return result;
}

补充一点CMTimeRange的知识:

typedef struct
{
    CMTime          start;      /*! @field start The start time of the time range. */
    CMTime          duration;   /*! @field duration The duration of the time range. */
} CMTimeRange;

start表示的是开始时间,duration表示的是时间范围的持续时间。所以这边缓冲的总进度就是两者相加了。

入门写到这里,下面是自定义一个播放管理器

三、自定义播放管理器

1.创建类并声明方法

想象一下一个播放管理器会有哪些方法,播放,暂停,开始播放网络音乐,开始播放本地音乐,甚至还有拉进度条来快进快退。代码如下:

//单例
+ (instancetype)sharedPlayerManager;

//暂停
- (void)pasuseMusic;

//播放
- (void)playMusic;

//准备去播放
- (void)prepareToPlayMusicWithUrl:(NSString *)url;

//本地播放方法
- (void)prepareToPlayMusicWithFilePath:(NSString *)musicFilePath;

//快进快退方法
- (void)playMusicWithSliderValue:(CGFloat)peogress;

2.相关方法的实现

趁热打铁,先写播放歌曲方法

// 播放网络歌曲
- (void)prepareToPlayMusicWithUrl:(NSString *)url
{
    if (!url) {
        return;
    }
    //判断当前有没有正在播放的item
    if (self.player.currentItem) {
        //移除观察者
        [self.player.currentItem removeObserver:self forKeyPath:@"status"];
        [self.player.currentItem removeObserver:self forKeyPath:@"loadedTimeRanges"];
    }
    //创建一个item
    AVPlayerItem *item =[AVPlayerItem playerItemWithURL:[NSURL URLWithString:url]];
    //观察item的加载状态
    [item addObserver:self forKeyPath:@"status" options:NSKeyValueObservingOptionNew context:nil];
    [item addObserver:self forKeyPath:@"loadedTimeRanges" options:NSKeyValueObservingOptionNew context:nil];
    //替换当前item
    [self.player replaceCurrentItemWithPlayerItem:item];
    //播放完成后自动跳到下一首
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(nextMusic) name:AVPlayerItemDidPlayToEndTimeNotification object:nil];

}

// 播放本地歌曲
- (void)prepareToPlayMusicWithFilePath:(NSString *)musicFilePath
{
    //判断当前有没有正在播放的item
    if (self.player.currentItem) {
        //移除观察者
        [self.player.currentItem removeObserver:self forKeyPath:@"status"];
        [self.player.currentItem removeObserver:self forKeyPath:@"loadedTimeRanges"];
    }
    //创建一个item
    AVPlayerItem *item =[AVPlayerItem playerItemWithURL:[NSURL fileURLWithPath:musicFilePath]];
    
    //观察item的加载状态
    [item addObserver:self forKeyPath:@"status" options:NSKeyValueObservingOptionNew context:nil];
    [item addObserver:self forKeyPath:@"loadedTimeRanges" options:NSKeyValueObservingOptionNew context:nil];
    //替换当前item
    [self.player replaceCurrentItemWithPlayerItem:item];
    //播放完成后自动跳到下一首
    [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(nextMusic) name:AVPlayerItemDidPlayToEndTimeNotification object:nil];
}

再写相关私有方法

#pragma mark - 私有方法
// 获取当前时间
- (NSInteger)fetchCurrentTime
{
    CMTime time = self.player.currentItem.currentTime;
    if (time.timescale == 0) {
        return 0;
    }
    return time.value/time.timescale;
}

// 获取总时间时间
- (NSInteger)fetchTotalTime
{
    CMTime time = self.player.currentItem.duration;
    if (time.timescale == 0) {
        return 0;
    }
    return time.value/time.timescale;
}

// 获取当前播放进度
- (CGFloat)fetchProgressValue
{
    return [self fetchCurrentTime]/(CGFloat)[self fetchTotalTime];
}

// 获取缓冲进度
- (float)availableDuration
{
    NSArray *loadedTimeRanges = [[self.player currentItem] loadedTimeRanges];
    CMTimeRange timeRange = [loadedTimeRanges.firstObject CMTimeRangeValue];// 获取缓冲区域
    float startSeconds = CMTimeGetSeconds(timeRange.start);
    float durationSeconds = CMTimeGetSeconds(timeRange.duration);
    float result = startSeconds + durationSeconds;// 计算缓冲总进度
    return result;
}

//将秒数转化成类似00:00的格式,用于界面显示
- (NSString *)changeSecondsTime:(NSInteger)time
{
    NSInteger min =time/60;
    NSInteger seconds =time % 60;
    return [NSString stringWithFormat:@"%.2ld:%.2ld",min,seconds];
}

监听响应

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
    if ([keyPath isEqualToString:@"status"]) {
        AVPlayerItemStatus status =[change[@"new"]integerValue];//change为string类型
        switch (status) {
            case AVPlayerItemStatusUnknown:
                NSLog(@"未知错误");
                break;
            case AVPlayerItemStatusReadyToPlay:
                //调用播放方法
                [self.player play];
                break;
            case AVPlayerItemStatusFailed:{
                NSLog(@"错误");
                break;
            }
            default:
                break;
        }
    } else if ([keyPath isEqualToString:@"loadedTimeRanges"]) {
        float timeInterval= [self availableDuration];
        NSInteger totalDuration = [self fetchTotalTime];
        NSLog(@"==%f", timeInterval / totalDuration);
    }
}

由于始终要刷新界面的进度条,所以我们要创建一个timer来时刻返回当前的时间。这里我用的是代理模式。同时加两个开关定时器的私有方法。

// timer懒加载
- (NSTimer *)timer {
    if (!_timer) {
        _timer =[NSTimer scheduledTimerWithTimeInterval:0.1 target:self selector:@selector(timerAction) userInfo:nil repeats:YES];
    }
    return _timer;
}

//定时器方法
- (void)timerAction {
    if ([self.delegate respondsToSelector:@selector(playManagerDelegateFetchTotalTime:currentTime:progress:)]) {
        //1.总时间  2.当期时间 3.当前进度
        NSString *totalTime = [self changeSecondsTime:[self fetchTotalTime]];//总时间
        NSString *currentTime =[self changeSecondsTime:[self fetchCurrentTime]];//当前时间
        CGFloat progress = [self fetchProgressValue];
        
        [self.delegate playManagerDelegateFetchTotalTime:totalTime  currentTime:currentTime  progress:progress];
    }
}

//开启定时器
- (void)startTimer
{
    [self.timer fire];
}

//关闭定时器
- (void)closeTimer
{
    [self.timer invalidate];
    self.timer = nil;  //置空
}

最后完成剩下的方法

// 暂停
- (void)pasuseMusic
{
    [self.player pause];
    [self closeTimer];
}

// 播放
- (void)playMusic
{
    [self.player play];
    [self startTimer];
}

//快进快退
- (void)playMusicWithSliderValue:(CGFloat)peogress{
    //滑动之前 先暂停音乐
    [self pasuseMusic];
    [self.player seekToTime:CMTimeMake([self fetchTotalTime] * peogress, 1) completionHandler:^(BOOL finished) {
        if (finished) {
            //活动结束继续播放
            [self playMusic];
        }
    }];
}

好了,到这边所有的方法都完成了。我把代码全部再贴上。
.h文件

#import 
#import 

@protocol YQPlayerManagerDelegate 
// 传递播放时间总时间等信息
-(void)playManagerDelegateFetchTotalTime:(NSString *)totalTime currentTime:(NSString *)currentTime progress:(CGFloat)progress;
// 传递播放的进度百分比
- (void)playManagerDelegateFetchLoadedTimeRanges:(CGFloat)loadPercent;
// 下一首歌
- (void)playNextMusic;
@end

@interface YQPlayerManager : NSObject

@property (nonatomic, weak) id  delegate;

//单例
+ (instancetype)sharedPlayerManager;

//暂停
- (void)pasuseMusic;

//播放
- (void)playMusic;

//准备去播放
- (void)prepareToPlayMusicWithUrl:(NSString *)url;

//本地播放方法
- (void)prepareToPlayMusicWithFilePath:(NSString *)musicFilePath;

//快进快退方法
- (void)playMusicWithSliderValue:(CGFloat)peogress;
@end

.m文件

#import "YQPlayerManager.h"

@interface YQPlayerManager()
@property (nonatomic, strong) AVPlayer *player;
@property (nonatomic, strong) NSTimer *timer;
@end

@implementation YQPlayerManager

// timer懒加载
- (NSTimer *)timer {
    if (!_timer) {
        _timer =[NSTimer scheduledTimerWithTimeInterval:0.1 target:self selector:@selector(timerAction) userInfo:nil repeats:YES];
    }
    return _timer;
}

//定时器方法
- (void)timerAction {
    if ([self.delegate respondsToSelector:@selector(playManagerDelegateFetchTotalTime:currentTime:progress:)]) {
        //1.总时间  2.当期时间 3.当前进度
        NSString *totalTime = [self changeSecondsTime:[self fetchTotalTime]];//总时间
        NSString *currentTime =[self changeSecondsTime:[self fetchCurrentTime]];//当前时间
        CGFloat progress = [self fetchProgressValue];
        [self.delegate playManagerDelegateFetchTotalTime:totalTime  currentTime:currentTime  progress:progress];
    }
}

//开启定时器
- (void)startTimer
{
    [self.timer fire];
}

//关闭定时器
- (void)closeTimer
{
    [self.timer invalidate];
    self.timer = nil;  //置空
}


//player懒加载
- (AVPlayer *)player
{
    if (_player == nil) {
        _player = [[AVPlayer alloc] init];
    }
    return _player;
}


//单例
+ (instancetype)sharedPlayerManager {
    static YQPlayerManager *handle = nil;
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        handle = [[YQPlayerManager alloc] init];
    });
    return handle;
}

// 暂停
- (void)pasuseMusic
{
    [self.player pause];
    [self closeTimer];
}

// 播放
- (void)playMusic
{
    [self.player play];
    [self startTimer];
}

// 播放网络歌曲
- (void)prepareToPlayMusicWithUrl:(NSString *)url
{
    if (!url) {
        return;
    }
    //判断当前有没有正在播放的item
    if (self.player.currentItem) {
        //移除观察者
        [self.player.currentItem removeObserver:self forKeyPath:@"status"];
        [self.player.currentItem removeObserver:self forKeyPath:@"loadedTimeRanges"];
    }
    //创建一个item
    AVPlayerItem *item =[AVPlayerItem playerItemWithURL:[NSURL URLWithString:url]];
    //观察item的加载状态
    [item addObserver:self forKeyPath:@"status" options:NSKeyValueObservingOptionNew context:nil];
    [item addObserver:self forKeyPath:@"loadedTimeRanges" options:NSKeyValueObservingOptionNew context:nil];
    //替换当前item
    [self.player replaceCurrentItemWithPlayerItem:item];
    //播放完成后自动跳到下一首
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(nextMusic) name:AVPlayerItemDidPlayToEndTimeNotification object:nil];

}

// 播放本地歌曲
- (void)prepareToPlayMusicWithFilePath:(NSString *)musicFilePath
{
    //判断当前有没有正在播放的item
    if (self.player.currentItem) {
        //移除观察者
        [self.player.currentItem removeObserver:self forKeyPath:@"status"];
        [self.player.currentItem removeObserver:self forKeyPath:@"loadedTimeRanges"];
    }
    //创建一个item
    AVPlayerItem *item =[AVPlayerItem playerItemWithURL:[NSURL fileURLWithPath:musicFilePath]];
    
    //观察item的加载状态
    [item addObserver:self forKeyPath:@"status" options:NSKeyValueObservingOptionNew context:nil];
    [item addObserver:self forKeyPath:@"loadedTimeRanges" options:NSKeyValueObservingOptionNew context:nil];
    //替换当前item
    [self.player replaceCurrentItemWithPlayerItem:item];
    //播放完成后自动跳到下一首
    [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(nextMusic) name:AVPlayerItemDidPlayToEndTimeNotification object:nil];
}

//快进快退
- (void)playMusicWithSliderValue:(CGFloat)peogress{
    //滑动之前 先暂停音乐
    [self pasuseMusic];
    [self.player seekToTime:CMTimeMake([self fetchTotalTime] * peogress, 1) completionHandler:^(BOOL finished) {
        if (finished) {
            //活动结束继续播放
            [self playMusic];
        }
    }];
}

- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
    if ([keyPath isEqualToString:@"status"]) {
        AVPlayerItemStatus status =[change[@"new"]integerValue];//change为string类型
        switch (status) {
            case AVPlayerItemStatusUnknown:
                NSLog(@"未知错误");
                break;
            case AVPlayerItemStatusReadyToPlay:
                // 调用播放方法 
                // 注意这里要改成[self playMusic];而不是还是原来的[self.player play],否则无法开启定时器!!!
                [self playMusic];
                break;
            case AVPlayerItemStatusFailed:{
                NSLog(@"错误");
                break;
            }
            default:
                break;
        }
    } else if ([keyPath isEqualToString:@"loadedTimeRanges"]) {
        float timeInterval= [self availableDuration];
        NSInteger totalDuration = [self fetchTotalTime];
        float percent = timeInterval /totalDuration;
        if (percent > 1) {
            percent = 1;
        }
        if ([self.delegate respondsToSelector:@selector(playManagerDelegateFetchLoadedTimeRanges:)]) {
            [self.delegate playManagerDelegateFetchLoadedTimeRanges:percent];
        }
    }
}

#pragma mark - 私有方法
- (void)nextMusic
{
    if ([self.delegate respondsToSelector:@selector(playNextMusic)]) {
        [self.delegate playNextMusic];
    }
}

// 获取当前时间
- (NSInteger)fetchCurrentTime
{
    CMTime time = self.player.currentItem.currentTime;
    if (time.timescale == 0) {
        return 0;
    }
    return time.value/time.timescale;
}

// 获取总时间时间
- (NSInteger)fetchTotalTime
{
    CMTime time = self.player.currentItem.duration;
    if (time.timescale == 0) {
        return 0;
    }
    return time.value/time.timescale;
}

// 获取当前播放进度
- (CGFloat)fetchProgressValue
{
    return [self fetchCurrentTime]/(CGFloat)[self fetchTotalTime];
}

// 获取缓冲进度
- (float)availableDuration
{
    NSArray *loadedTimeRanges = [[self.player currentItem] loadedTimeRanges];
    CMTimeRange timeRange = [loadedTimeRanges.firstObject CMTimeRangeValue];// 获取缓冲区域
    float startSeconds = CMTimeGetSeconds(timeRange.start);
    float durationSeconds = CMTimeGetSeconds(timeRange.duration);
    float result = startSeconds + durationSeconds;// 计算缓冲总进度
    return result;
}

//将秒数转化成类似00:00的格式,用于界面显示
- (NSString *)changeSecondsTime:(NSInteger)time
{
    NSInteger min =time/60;
    NSInteger seconds =time % 60;
    return [NSString stringWithFormat:@"%.2ld:%.2ld",min,seconds];
}

3.使用管理器

在视图控制器中使用,上代码:

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    YQPlayerManager *manager = [YQPlayerManager sharedPlayerManager];
    [manager prepareToPlayMusicWithUrl:@"http://m2.music.126.net/lpeVipLJshTxA-T7xjFI2g==/1046735069650768.mp3"];
    manager.delegate = self;
}

-  (void)playManagerDelegateFetchTotalTime:(NSString *)totalTime currentTime:(NSString *)currentTime progress:(CGFloat)progress
{
    NSLog(@"%@---%@---%f", totalTime, currentTime, progress);
}

- (void)playManagerDelegateFetchLoadedTimeRanges:(CGFloat)loadPercent
{
    NSLog(@"%f", loadPercent);
}

- (void)playNextMusic
{
    NSLog(@"playNextMusic");
}

结果:

结果展示.gif

最后

到这里就全部搞定了,喜欢的点个赞呗~

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