9

我正在尝试实现一个 UIScrollView，其中水平平移滚动滚动视图中的图片，但垂直平移执行我拥有的另一个操作。现在，我有一个 UIScrollView，它在禁用垂直滚动的情况下分页，可以很好地滚动浏览图片，但是我疯狂地试图找到一种方法来拦截垂直平底锅并调用我自己的方法，而不是垂直平底锅被吃掉滚动视图。我能够做到 

    UIPanGestureRecognizer *panUp = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePanGesture:)];
[self.scrollView addGestureRecognizer:panUp];
[scrollView.panGestureRecognizer setEnabled:NO];

这让我可以完全控制我的 handlePanGesture: 方法中的平移，但这并不是特别有用，因为我觉得我基本上要重写我试图避免的所有滚动逻辑。任何有关如何实现这一目标的帮助或指导将不胜感激。

谢谢！

4

3 回答 3

10

从 iOS 5 开始，UIScrollView 公开其UIPanGestureRecognizer. 将您的自定义滑动设置delegate为self并将gestureRecognizer 设置为属性或ivar，并使您的类符合<UIGestureRecognizerDelegate>协议。然后，UIGestureRecognizerDelegate像– gestureRecognizer:shouldRecognizeSimultaneouslyWithGestureRecognizer:这样实现：

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
    if ([gestureRecognizer isEqual:self.swipe] && [otherGestureRecognizer isEqual:self.scrollView.panGestureRecognizer])
    {
         return NO;
    }
    return YES; // the default for this method
}
于 2012-10-03T00:23:17.040 回答
9

我添加了一个UIPanGestureRecognizer这样的设置gestureRecognizer:shouldRecognizeSimultaneouslyWithGestureRecognizer:：

- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer {
    if ([gestureRecognizer isEqual:self.panGesture] && [otherGestureRecognizer isEqual:self.collectionView.panGestureRecognizer]){
        return YES;
    }
    return NO;
}

我还添加了签到gestureRecognizerShouldBegin:

- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer {
    if ([gestureRecognizer isEqual:self.panGesture]) {
        if (gestureRecognizer.numberOfTouches > 0) {
            CGPoint point = [gestureRecognizer locationOfTouch:0 inView:gestureRecognizer.view];
            CGFloat distX = abs(self.collectionView.lastTouchPos.x - point.x);
            CGFloat distY = abs(self.collectionView.lastTouchPos.y - point.y);
            if (distX > distY) {
                return NO;
            }
        } else {
            return NO;
        }
    }
    return YES;
}

仅self.panGesture在向上或向下平移时使用。

更新

https://stackoverflow.com/a/8603839/667834似乎有更好的方法gestureRecognizerShouldBegin

- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer {
    if ([gestureRecognizer isEqual:self.panGesture]) {
        if (gestureRecognizer.numberOfTouches > 0) {
            CGPoint translation = [self.panGesture velocityInView:self.collectionView];
            return fabs(translation.y) > fabs(translation.x);
        } else {
            return NO;
        }
    }
    return YES;
}
于 2013-11-13T05:21:24.677 回答
4

如果您想使用平移手势，我认为这将很困难，因为滚动视图使用了这些手势。但是，如果您可以使用滑动，则很容易实现。

    UISwipeGestureRecognizer *swipe = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(handlePanGesture:)];
    swipe.direction = UISwipeGestureRecognizerDirectionDown | UISwipeGestureRecognizerDirectionUp;
    [self.scrollView addGestureRecognizer:swipe];

我对此进行了测试，调用处理程序效果很好，并且您不需要禁用滚动视图的平移手势识别器（在我的测试中，滚动视图足够高并且内容足够短以至于没有垂直滚动 - - 我不知道这是否有必要）。

于 2012-10-02T23:59:08.733 回答