UITableView height equal to contentSize height

问题

I have a scroll view and inside of if couple labels and a tableView. I would like for that tableView to be scrolled by a outer scrollView and not the tableView's scrollView, so what I did is to set constraint for tableView height to be equal to contentSize height. But I have this problem that it is sized correctly only when push animation is completed (and viewDidLayoutSubviews gets called, I guess)

override func viewDidLayoutSubviews() {
    super.viewDidLayoutSubviews()
    tableHeightConstraint?.constant = tableViewController.tableView.contentSize.height
}

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回答1:

Content size will refresh with scroll view logic. So layout subviews is surely not enough. I have one case where I resize table view depending on it's content. What I do is use intrinsic size (it is that compression priority thing in storyboard). I subclass the table view and override these:

override var contentSize:CGSize {
    didSet {
        self.invalidateIntrinsicContentSize()
    }
}

override var intrinsicContentSize: CGSize {
    self.layoutIfNeeded()
    return CGSize(width: UIViewNoIntrinsicMetric, height: contentSize.height)
}

The rest may then be done with constraints. Im my case I do not resize it further then it's superview but you do what you must. Still a bit of caution here: If this is not restricted you destroy the table view dequeuing feature and all the cells may be loaded instantly which may consume loads of memory and CPU. I would avoid that if possible. And if not, the next best thing is using a vertical stack view on a scroll view which should produce the same result you seem to expect.

来源：https://stackoverflow.com/questions/52056119/uitableview-height-equal-to-contentsize-height