问题描述
有没有办法知道 UIScrollView 是到达顶部还是底部?可能在方法中:
Is there a way to know if a UIScrollView has reached the top or bottom? Possibly in the method:
- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
推荐答案
在你的类中实现UIScrollViewDelegate,然后添加:
Implement the UIScrollViewDelegate in your class, and then add this:
-(void)scrollViewDidScroll: (UIScrollView*)scrollView { float scrollViewHeight = scrollView.frame.size.height; float scrollContentSizeHeight = scrollView.contentSize.height; float scrollOffset = scrollView.contentOffset.y; if (scrollOffset == 0) { // then we are at the top } else if (scrollOffset + scrollViewHeight == scrollContentSizeHeight) { // then we are at the end } }
希望这就是你所追求的!否则,通过在上面的代码中添加更多条件和 NSLog 滚动偏移的值来进行修补.
Hope this is what you are after! Else have a tinker by adding more conditions to the above code and NSLog the value of scrollOffset.