震动检测iPhone 3.0不工作

我有一个ViewController，它与触发动作的按钮完美配合。我想用一个震动事件替换这个按钮，所以我在谷歌上搜索了一下，并创建了一个震动检测器类，它在UIView中显示

我的实施情况如下：

@implementation ShakeDetector

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

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

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

@end

但我不能让它工作。。。有什么帮助吗

谢谢

放：

    -(BOOL)canBecomeFirstResponder
{
    return YES;
}

请注意：

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

您也可以在VIEWWILLEXPEND和VIEWWILLEXPEND中写入它