UITableViewCell - When are the bounds properly set in iOS 10 - uitableview

Question

I want to create a round UIView (myView) inside a UITableViewCell
Prior to iOS 10 I was using func awakeFromNib() to do so like that:
class MyCell: UITableViewCell {
#IBOutlet var myView: UIView!
override func awakeFromNib() {
super.awakeFromNib()
print(myView.bounds.height)
myView.layer.cornerRadius = myView.bounds.height/2
myView.layer.masksToBounds = true
}
}
myView height and with are set to 30 via an AutoLayout constraint in my storyboard.
But print(myView.bounds.height) show 1000.0 in the console.
So the corner radius instruction set a radius to 500 and myView disappear completely.
Is the UITableViewCell life cycle change in iOS 10 ?
Is the function where the view.bounds are set change in iOS 10 ?
How can do a set a cornerRadius to half my view height in iOS 10 ?
Here is a minimal projet to reproduce the issue
To have a result close to what I want I need to add in my UITableViewController:
override func viewDidAppear(animated: Bool) {
super.viewDidAppear(animated)
tableView.reloadData()
}
But I'm quite sure this is not optimal ...

Answer 1

I had the same problem and found two ways to fix it. Both enforce the cell to layout subviews
First solution:
override func awakeFromNib() {
super.awakeFromNib()
self.setNeedsLayout()
self.layoutIfNeeded()
}
Second way:
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath)
cell.setNeedsLayout()
cell.layoutIfNeeded()
return cell
}

Answer 2

I had exactly the same issue, with the same size of 1000.0 when asking for the bounds of a subview.
As the frame or bounds values are not reliable anymore I had to declare an IBOutlet for the height constraint defined in my storyboard and use it to set the corner radius of my subview.
class MyCell: UITableViewCell {
#IBOutlet var myView: UIView!
#IBOutlet var myViewHeightConstraint: NSLayoutConstraint!
override func awakeFromNib() {
super.awakeFromNib()
print(myView.bounds.height)
myView.layer.cornerRadius = myViewHeightConstraint.constant / 2
myView.layer.masksToBounds = true
}
}
This will enable you to remove the reloadData call which is really not optimal as you said.

Answer 3

My observation is that iOS 10 / TVOS 10 is not laying out auto layout based views before calling awakeFromNib, but is laying out views using autoresizing masks before calling the same method.
Removing auto layout constraints and using the new Autoresizing settings in storyboards solved it for me.
To me this makes Autolayout less reliable than autoresizing masks. I also 'feel' a performance improvement after switching out of Autolayout. I cannot say for sure though as I am on TVOS and the Core Animation instrument doesn't work for TVOS.