暂停并使用AVAudioSession播放音频

Question

我有1个控制器。首先我开始播放audio1。我使用此代码：

- (void)viewDidLoad 
{ 

    //code to not turn off audio with using mute switch 

    [[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:nil]; 
    [[AVAudioSession sharedInstance] setActive: NO error: nil]; 

     //code to play audio 

     NSString *soundFilePath = [NSString stringWithFormat:@"%@/%@.mp3",[[NSBundle mainBundle] resourcePath], @"sound"]; 
     NSURL *soundFileURL = [NSURL fileURLWithPath:soundFilePath]; 
     _player = [[AVAudioPlayer alloc] initWithContentsOfURL:soundFileURL error:nil]; 
     _player.numberOfLoops = -1; 
     [_player play]; 
} 

但是，当我隐藏我的应用程序音频没有暂停。当我隐藏我的应用程序并在应用程序到达前台时暂停点播放时，我想暂停音频。怎么做？

Answer 1

你可以使用通知检测应用程序将背景/前景。

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(appEnterBackground:) name:@"enterBackGroundNotification" object:nil]; 
[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(appEnterForeground:) name:@"enterForeGroundNotification" object:nil]; 

- (void)appEnterBackground:(NSNotification *) notification { 
    [_player pause]; 
} 

- (void)appEnterForeground:(NSNotification *) notification { 
    [_player play]; 
} 

Answer 2

为此，您需要为应用程序在后台和前台添加通知。

申报玩家第一

AVAudioPlayer *player; 

在viewDidLoad中

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(appEnterBackgroundActive:) name:UIApplicationDidEnterBackgroundNotification object:nil]; 

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(appEnterForegroundActive:) name:UIApplicationWillEnterForegroundNotification object:nil]; 

[[AVAudioSession sharedInstance] setCategory:AVAudioSessionCategoryPlayback error:nil]; 

[[AVAudioSession sharedInstance] setActive: NO error: nil]; 

//code to play audio 
NSString *soundFilePath = [NSString stringWithFormat:@"%@/%@.mp3",[[NSBundle mainBundle] resourcePath], @"alarm_tone"]; 
NSURL *soundFileURL = [NSURL fileURLWithPath:soundFilePath]; 
player = [[AVAudioPlayer alloc] initWithContentsOfURL:soundFileURL error:nil]; 
player.numberOfLoops = -1; 
[player play]; 

添加该代码添加输入后台方法。

-(void)appEnterBackgroundActive:(NSNotification*)note 
{ 
    [player pause]; 
} 

添加输入前台方法。

-(void)appEnterForegroundActive:(NSNotification*)note 
{ 
    [player play]; 
}