Question

Hello
I’m trying to have it, so once the user shakes the device. I want a sound to play. However once I shake the device it crashes, this is the code which I have used

- (BOOL)canBecomeFirstResponder
{
    return YES;
}

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];

    [self becomeFirstResponder];
}

- (void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event
{
    if(motion == UIEventSubtypeMotionShake)
    {
        NSString *path = [[NSBundle mainBundle] pathForResource:@"sound" ofType:@"wav"];
        if (theAudio) [theAudio release];
        NSError *error = nil;
        theAudio = [[AVAudioPlayer alloc] initWithContentsOfURL:[NSURL fileURLWithPath:path] error:&error];
        if (error)
            NSLog(@"%@",[error localizedDescription]);
        theAudio.delegate = self;
        [theAudio play];    
    }
}

And this is the crash report

2011-04-19 19:25:44.337 iApp[314:207] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '*** -[NSURL initFileURLWithPath:]: nil string parameter'
*** Call stack at first throw:
(
    0   CoreFoundation                      0x00fc3be9 __exceptionPreprocess + 185
    1   libobjc.A.dylib                     0x00db85c2 objc_exception_throw + 47
    2   CoreFoundation                      0x00f7c628 +[NSException raise:format:arguments:] + 136
    3   CoreFoundation                      0x00f7c59a +[NSException raise:format:] + 58
    4   Foundation                          0x00055b12 -[NSURL(NSURL) initFileURLWithPath:] + 90
    5   Foundation                          0x00055aa0 +[NSURL(NSURL) fileURLWithPath:] + 72
    6   iApp                               0x0000305d -[AppViewController motionEnded:withEvent:] + 256
    7   UIKit                               0x002dc07c -[UIWindow sendEvent:] + 350
    8   UIKit                               0x002bf37a -[UIApplication sendEvent:] + 447
    9   UIKit                               0x002c311b _UIApplicationHandleEvent + 1921
    10  GraphicsServices                    0x017daa36 PurpleEventCallback + 1550
    11  CoreFoundation                      0x00fa5064 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 52
    12  CoreFoundation                      0x00f056f7 __CFRunLoopDoSource1 + 215
    13  CoreFoundation                      0x00f02983 __CFRunLoopRun + 979
    14  CoreFoundation                      0x00f02240 CFRunLoopRunSpecific + 208
    15  CoreFoundation                      0x00f02161 CFRunLoopRunInMode + 97
    16  GraphicsServices                    0x017d9268 GSEventRunModal + 217
    17  GraphicsServices                    0x017d932d GSEventRun + 115
    18  UIKit                               0x002c842e UIApplicationMain + 1160
    19  iApp                               0x0000295c main + 102
    20  iApp                               0x000028ed start + 53
)
terminate called after throwing an instance of 'NSException'

Answer 1

Given the crash report reason:

reason: '*** -[NSURL initFileURLWithPath:]: nil string parameter'

along with the last executed line in your app’s code:

   6   iApp               0x0000305d -[AppViewController motionEnded:withEvent:] + 256

I would think that your sound.wav file is missing:

    NSString *path = [[NSBundle mainBundle] pathForResource:@"sound" ofType:@"wav"];

I suggest your make sure:

1. the sound.wav file is in your project
2. is case sensitively spelled “sound.wav”

Hope this helps.