ios - 如何使 UISwipeGestureRecognizer 在 UIScrollView 中工作

Question

我在 viewDidLoad 中有这个:

UISwipeGestureRecognizer *swipeUp = [[UISwipeGestureRecognizer alloc] initWithTarget:self action:@selector(hideHeaderBar:)];
swipeUp.direction = UISwipeGestureRecognizerDirectionUp;
swipeUp.

[self.view addGestureRecognizer:swipeUp];

然后我在 View 中有一个 UIScrollView。出于某种原因，当我在 ScrollView 上向上滚动时，它不会调用选择 hideHeaderBar。对此有任何修复吗？

-(void)hideHeaderBar:(UISwipeGestureRecognizer*)swipeRecognizer{
    POPSpringAnimation *fadeButton = [POPSpringAnimation animationWithPropertyNamed:kPOPLayerOpacity];
    fadeButton.toValue = @(0.0);
    fadeButton.springBounciness = 0.f;

    [settingsButton.layer pop_addAnimation:fadeButton forKey:@"fadeButton"];
    [heartButton.layer pop_addAnimation:fadeButton forKey:@"fadeButton"];
    [conversationsButton.layer pop_addAnimation:fadeButton forKey:@"fadeButton"];

    POPSpringAnimation *hideHeader = [POPSpringAnimation animationWithPropertyNamed:kPOPLayerPositionY];
    hideHeader.toValue = @(-10);
    hideHeader.springBounciness = 5.f;
    [headerBar.layer pop_addAnimation:hideHeader forKey:@"hideHeaderAnim"];
    POPSpringAnimation *hideBody = [POPSpringAnimation animationWithPropertyNamed:kPOPViewFrame];
    hideBody.toValue = [NSValue valueWithCGRect:CGRectMake(0, -10, screenSize.size.width, screenSize.size.height)];
    hideBody.springBounciness = 5.f;
    [homeScrollView.layer pop_addAnimation:hideBody forKey:@"hideBodyAnim"];


}

需要注意的是 UIScrollView 位于 subview Controller 中(位于 UIScrollView 本身内)

[self addChildViewController:settingsViewController];
[homeScrollView addSubview:settingsViewController.view];
[settingsViewController.view setFrame:CGRectMake(0, 0, screenSize.size.width, screenSize.size.height)];
[settingsViewController didMoveToParentViewController:self];

Answer 1

当然，您可以使用滑动手势识别器，但 ScrollView 已经可以处理滑动。

这里可能更好和更合适做的是将您的 View Controller 设置为 UIScrollViewDelegate 并实现此方法:

scrollViewDidScroll:

要仅检测滚动向上的时间，您可以向 View Controller 添加一个如下所示的属性:

@property (nonatomic) CGFloat lastContentOffset;

然后简单地做类似的事情:

- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    if (self.lastContentOffset > scrollView.contentOffset.y)
    {
        NSLog(@"Scrolling Up");
    }
    else if (self.lastContentOffset < scrollView.contentOffset.y)
    {
        NSLog(@"Scrolling Down");
    }

    self.lastContentOffset = scrollView.contentOffset.y;
}

(上面的代码是我找的 in this very related question )

当“向上滚动”行出现时，是时候隐藏您的标题栏了。