Shake Detection iPhone 3.0 not working

I have a ViewController that works perfectly with a button that trigger an action. I would like to replace the button with a shake event so I've googled it around and created a ShakeDetector class that ineherits from UIView

and my implementation is as follow:

@implementation ShakeDetector

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

    - (void)motionEnded:(UIEventSubtype)motion withEvent:(UIEvent *)event
    {
        if (motion == UIEventSubtypeMotionShake )
        {
            // User was shakin开发者_JS百科g the device. Post a notification named "shake".
            //[[NSNotificationCenter defaultCenter] postNotificationName:@"spin" object:self];
            NSLog(@"sss");
        }
    }

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

@end

But I can't make it work... any help?

Thanks

---

Put :

    -(BOOL)canBecomeFirstResponder
{
    return YES;
}

and for your view :

  - (void)viewDidAppear:(BOOL)animated {
    [super viewDidAppear:animated];
    [self becomeFirstResponder];
}
- (void)viewDidDisappear:(BOOL)animated {
    [self resignFirstResponder];
    [super viewDidDisappear:animated];
}

You can also write it in viewWillAppear and viewWillDisappear