ScrollView在按钮上拖动时不滚动 [英] ScrollView not scrolling when dragging on buttons

问题描述

我有一个滚动视图，用于滚动时，它没有按钮。现在它，并且当拖动鼠标（在模拟器上）没有发生任何事情（我认为，因为按钮被推动）。

I have a scroll view that used to scroll when it didn't have buttons all over it. Now it does, and when dragging the mouse (on simulator) nothing happens (i think because the buttons are being pushed). How can I make this right?

推荐答案

这是因为 UIButton UIScrollView 的子视图（我假设按钮是作为子视图添加）在跟踪触摸，而不是滚动视图。 UIScrollView 方法 touchesShouldCancelInContentView 是这里的关键。根据其描述：如果视图不是 UIControl 对象，则默认返回值为YES;否则返回 NO 。，即 UIControl 对象（按钮）， UIScrollView 不会尝试取消触摸来防止滚动。

This is happening because UIButton subviews of the UIScrollView (I assume buttons are added as subviews in your case) are tracking the touches and not the scroll view. UIScrollView method touchesShouldCancelInContentView is the key here. According to its description: "The default returned value is YES if view is not a UIControl object; otherwise, it returns NO.", i.e. for UIControl objects (buttons), UIScrollView does not attempt to cancel touches which prevents scrolling.

因此，允许使用按钮滚动：

So, to allow scrolling with buttons:

1. 确保 UIScrollView 属性 canCancelContentTouches 设置为 YES 。


2. 子类 UIScrollView 并覆盖 touchesShouldCancelInContentView 以返回 YES 当内容视图对象为 UIButton 时，如下所示：

1. Make sure UIScrollView property canCancelContentTouches is set to YES.
2. Subclass UIScrollView and override touchesShouldCancelInContentView to return YES when content view object is a UIButton, like this:

- (BOOL)touchesShouldCancelInContentView:(UIView *)view
{
    if ( [view isKindOfClass:[UIButton class]] ) {
        return YES;
    }

    return [super touchesShouldCancelInContentView:view];
}

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