// 添加回到顶部按钮
_topBtn = [UIButton buttonWithType:UIButtonTypeCustom];
_topBtn.frame = CGRectMake(self.view.frame.size.width-60, self.view.frame.size.height-100, 40, 40);
[_topBtn setBackgroundImage:[UIImage imageNamed:@"nearby_return_top_btn"] forState:UIControlStateNormal];
[_topBtn addTarget:self action:@selector(backToTopButton) forControlEvents:UIControlEventTouchUpInside];
_topBtn.clipsToBounds = YES;
_topBtn.hidden = YES;
[self.view addSubview:_topBtn];
// MARK: 计算偏移量
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
//MARK:列表滑动偏移量计算
CGPoint point = [self.tableView contentOffset];
if (point.y >= 50) {
self.topBtn.hidden = NO;
[self.view bringSubviewToFront:self.topBtn];
} else {
self.topBtn.hidden = YES;
}
}
//MARK: 点击移动到顶部
- (void)backToTopButton{
[self.tableView setContentOffset:CGPointMake(0, 0) animated:YES];
}
