带有导航栏大标题的UITableView怪异的滚动行为，滚动到顶部时，顶部的反弹效果自动切断/生涩

Question

I have a UITableView with multiple sections with the header, collapsable/expandable. And also a tableHeaderView with custom UIView .

Using custom section header UIView and also custom UITableViewCell .

When all sections and rows are fully expanded, there is this weird scroll behavior, when I'm scrolling to the top (scroll down), when I reach the very top, the large navigation bar title should follow my scroll down gesture and animate down its way (Bounce effect). However, in this case, the bounce effect did not happen, the moment I scrolled to the top and try to scroll more for bounce effect, the scroll automatically got cut off and the navigation bar automatically becomes a small title.

Surprisingly, when I collapsed all the rows of the first section, the scroll behavior goes back to normal.

Here's a gif to show my screen recording.

https://i.imgur.com/WwXmpmZ.gifv

I have set the following to my UITableView :

self.tableView.contentInset = UIEdgeInsets(top: 0, left: 0, bottom: 15, right: 0)
self.tableView.estimatedRowHeight = 0 
self.tableView.estimatedSectionHeaderHeight = 0
self.tableView.estimatedSectionFooterHeight = 0

I have also tried:

self.tableView.contentInsetAdjustmentBehavior = .never

This indeed solved the weird scrolling behavior, however it causes my section headers and rows to overlap with my tableHeaderView.

The way I handle the collapse/expand. If the object property isCollapsed is true, I just simply return 0 row for that section:

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

    if section == self.scheduleCount {
        //Last section
        return self.dataSource.count
    }

    guard let schedule = self.itineraryDataSource?.schedule[section] else { return 0 }

    if schedule.isCollapsed {
        return 0
    } else {
        return schedule.items.count
    }
}

These are all the height delegates, the last section is having different UITableViewCell , hence the different height.

func tableView(_ tableView: UITableView, heightForHeaderInSection section: Int) -> CGFloat {

    if section == self.scheduleCount {
        //Last section
        return 40
    }

    return 64
}

func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
    if indexPath.section == self.scheduleCount {
        //Last section
        return 112
    } else {
        return 76
    }
}

Answer 1

Managed to fix this.

Turns out I was returning UIView for my viewForHeaderInSection and I wasn't using tableView.dequeueReusableHeaderFooterView . I literally init a new xib UIView every time I scroll the tableView which causes it to automatically adjust the content inset, hence, caused the jerky scroll.

So, I created new custom xib for my section header view with type UITableViewHeaderFooterView , and simply return it at viewForHeaderInSection .

func tableView(_ tableView: UITableView, viewForHeaderInSection section: Int) -> UIView? {
    let dayHeaderView = tableView.dequeueReusableHeaderFooterView(withIdentifier: "ItineraryDayHeaderView") as? ItineraryDayHeaderView

    // Configure View...

    return dayHeaderView
}