暫停並使用AVAudioSession播放音頻

Question

我有1個控制器。首先我開始播放audio1。我使用此代碼：

- (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，當我隱藏我的應用程序音頻沒有暫停。當我隱藏我的應用程序並在應用程序到達前臺時暫停點播放時，我想暫停音頻。怎麼做？

Answer 1

你可以使用通知檢測應用程序將背景/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

爲此，您需要爲應用程序在後臺和前臺添加通知。

申報玩家第一

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]; 

添加該代碼添加輸入後臺方法。

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

添加輸入前臺方法。

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