off a sound effect with NSUserDefaults

问题

i try to off a sound effect on my app

play method is ' [myMusic play];

-(void)viewDidLoad {
     BOOL soundIsOff = [defaults boolForKey:@"sound_off"];
     //the problem is here 
     //xcode compiler doesn't copile this code 
     [myMusic play] = soundIsOff;

}

sound code : ' ///sound effect

 NSString * musicSonati = [[NSBundle mainBundle] pathForResource:@"sound"      ofType:@"wav"];
 myMusic = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL     fileURLWithPath:musicSonati] error:NULL];
 myMusic.delegate = self;
 myMusic.numberOfLoops = 0;

Shake API Code :

- (void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event {

 if (event.subtype == UIEventSubtypeMotionShake)

  //Play sound :
  [myMusic play] ; 
 }
}

回答1:

Looks like you are trying to assign a value to a method call. That is why you are getting the compiler error:

[myMusic play] = soundIsOff //This does not work.

You probably want something like this:

if(!soundIsOff) {
    [myMusic play];
}

The question is unclear however, so this is a guess at this point.

回答2:

I am confused by the question, but if what you want is to stop the sound, then you just need:

[myMusic stop];

回答3:

Like the others, I can only guess at what you want to do here. Perhaps you are trying to do this:

soundIsOff ? [music stop] : [music play];

来源：https://stackoverflow.com/questions/2554905/off-a-sound-effect-with-nsuserdefaults