相关疑难解决方法(0)

我正在检测用户是否已按下2秒钟:

UILongPressGestureRecognizer *longPress = [[UILongPressGestureRecognizer alloc]
                                             initWithTarget:self 
                                             action:@selector(handleLongPress:)];
        longPress.minimumPressDuration = 2.0;
        [self addGestureRecognizer:longPress];
        [longPress release];

这就是我处理长按的方式:

-(void)handleLongPress:(UILongPressGestureRecognizer*)recognizer{
    NSLog(@"double oo");
}

当我按下超过2秒钟时,文本"double oo"被打印两次.为什么是这样？我该怎么办？