水平滚动UIScrollView与垂直平移手势

Question

我正在尝试实现UIScrollView,其中水平平移滚动浏览滚动视图中的图片,但垂直平移执行我的另一个操作.现在我有一个UIScrollView分页显示垂直滚动禁用,可以很好地滚动浏览图片,但我疯了,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只是被吃掉了滚动视图.我能够做到

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

这使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将重写所有我想避免的滚动逻辑.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!

Answer 1

从iOS 5开始,UIScrollView 暴露它UIPanGestureRecognizer.将自定义滑动设置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,实施UIGestureRecognizerDelegate的– gestureRecognizer:shouldRecognizeSimultaneouslyWithGestureRecognizer:,像这样:

- (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
}

Answer 2

我添加了一个像这样的UIPanGestureRecognizer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;
}

我还加了一张支票 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

/sf/answers/602268761/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;
}

Answer 3

我认为如果您想使用平移手势，这会很困难，因为滚动视图使用了这些手势。但是，如果您可以使用滑动操作，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，内容足够短，因此没有垂直滚动 - - 我不知道这是否有必要）。