iphone - 控制 UIScrollView 超出范围？

Question

我想知道如何允许用户滚动到 UIScrollView 的范围之外？

Answer 1

您可以尝试将触摸事件从超级视图的各种 UIView 方法转发到滚动视图，看看是否可行。例如：

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    [scrollView touchesBegan:touches withEvent:event];
}
// etc

或者您可以尝试在超级视图上使用 UIPanGestureRecognizer 并在获得平移事件时显式设置滚动视图偏移量。例如：

- (void)handlePan:(UIPanGestureRecognizer *)pan
{
    scrollView.contentOffset = [pan translationInView:scrollView];
}
// Or something like that.

Answer 2

尝试子类化UIScrollView和覆盖hitTest:withEvent:，以便UIScrollView拾取触及其边界之外。像这样的东西：

@interface MagicScrollView : UIScrollView
@end

@implementation MagicScrollView

- (UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event {
    // Intercept touches 100pt outside this view's bounds on all sides
    if (CGRectContainsPoint(CGRectInset(self.bounds, -100, -100), point)) {
        return self;
    }
    return nil;
}

@end

您可能还需要覆盖pointInside:withEvent:的UIScrollView超级视图，具体取决于您的布局。

有关更多信息，请参阅以下问题：interaction beyond bounds of uiview