当用户向下滚动75％时，在uiscrollview中自动回发

Question

如何检查用户是否向下滚动75％？我想实现一个回发来加载更多的数据，但我不知道如何实现这个...如果有人能指出我正确的方向或展示一些示例代码，我将不胜感激？

Answer 1

First you need to set your scrollview delegate. And on scrollViewDidScroll method you need to calculate scroll position. This should cover your goals

- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    if ((scrollView.contentOffset.y + scrollView.bounds.size.height)/scrollView.contentSize.height) > 0.75) {
        // do stuff
    }

}