如何保持聲音關閉

Question

我有兩個按鈕。一個顯示聲音何時播放，另一個顯示聲音未播放。但是，當我將其關閉並切換視圖控制器時。我回到主菜單視圖控制器聲音重新開始。我想根據用戶設置保持開啓或關閉聲音。

 (IBAction)pauseSound 
{ 
    BOOL shouldPlaySound = YES; 
    [[NSUserDefaults standardUserDefaults] setBool:shouldPlaySound forKey:@"shouldPlaySound"]; 
    if (![sound isPlaying]) { 
     [sound play]; 
     [soundButton setBackgroundImage:[UIImage imageNamed:@"SoundOn.png"] forState:UIControlStateNormal]; 
    }else { 
     [sound pause]; 
     [soundButton setBackgroundImage:[UIImage imageNamed:@"SoundOff.png"] forState:UIControlStateNormal]; 
     } 
    [[NSUserDefaults standardUserDefaults] synchronize]; 
} 

Answer 1

一個好辦法做到這一點是節約用是否在NSUserDefaults播放聲音，這樣設置是由您的應用程序記住。設置即通過

BOOL shouldMuteSound = ...//set it corresponding to your button presses/visibility 
[[NSUserDefaults standardUserDefaults] setBool:shouldMuteSound forKey:@"shouldMuteSound"]; 
//call this to immediatly update the userDefaults 
[[NSUserDefaults standardUserDefaults] synchronize]; 

，並通過

BOOL shouldMuteSound = [[NSUserDefaults standardUserDefaults] boolForKey:@"shouldMuteSound"]; 

加載它，我起先不明白的是，按鈕是播放的聲音相同的viewController內。該代碼可以幫助您：

-(void)viewDidAppear:(BOOL)animated{ 
    [super viewDidAppear:animated]; 
    BOOL shouldMuteSound = [[NSUserDefaults standardUserDefaults] boolForKey:@"shouldMuteSound"]; 
    if(!shouldMuteSound){ 
     [self playSound]; 
    }else{ 
     [self stopSound]; 
    } 
} 

- (void)playSound{ 
    if(!sound){ 
     NSString *path = [[NSBundle mainBundle] pathForResource:@"Main Menu" ofType:@"mp3"]; 
     sound = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:path] error:NULL]; 
     sound.numberOfLoops = -1; 
    } 
    if (![sound isPlaying]){ 
     [sound play]; 
    } 
    [soundButton setBackgroundImage:[UIImage imageNamed:@"SoundOn.png"] forState:UIControlStateNormal]; 
} 

- (void)stopSound{ 
    [sound pause]; 
    [soundButton setBackgroundImage:[UIImage imageNamed:@"SoundOff.png"] forState:UIControlStateNormal]; 
} 

- (IBAction)soundButtonTapped{ 
    BOOL shouldMuteSound = [[NSUserDefaults standardUserDefaults] boolForKey:@"shouldMuteSound"]; 
    shouldMuteSound = !shouldMuteSound; 
    [[NSUserDefaults standardUserDefaults] setBool:shouldMuteSound forKey:@"shouldMuteSound"]; 
    [[NSUserDefaults standardUserDefaults] synchronize]; 
    if(shouldMuteSound){ 
     [self stopSound]; 
    }else{ 
     [self playSound]; 
    } 
}