translatesAutoresizingMaskIntoConstraints needs to be set to false when: You Create a UIView-based object in code (Storyboard/NIB will set it for you if the file has autolayout enabled), And you want to use auto layout for this view rather than frame-based layout, And the view will be added to a view hierarchy that is using auto … Read more
My own best answer so far involves setting the tableHeaderView once and forcing a layout pass. This allows a required size to be measured, which I then use to set the frame of the header. And, as is common with tableHeaderViews, I have to again set it a second time to apply the change. – … Read more
Based upon a review of your code, a few comments: You generally don’t need to adjust constraints when a view appears. If you find yourself doing this, it often means that you haven’t configured your storyboard correctly (or at least, not efficiently). The only time you really need to set/create constraints is either (a) you’re … Read more
You have to override updateViewConstraints() in your UIViewController and set the height constraint’s constant to tableView.contentSize.height: override func updateViewConstraints() { tableHeightConstraint.constant = tableView.contentSize.height super.updateViewConstraints() } Then you have to make sure that Label2 has a top constraint that is greaterThanOrEqual to the table view’s bottom. And you also have to change the table view’s height … Read more
Update for Swift 3/Swift 4: As of iOS 8, you can and should activate your constraints by setting their isActive property to true. This enables the constraints to add themselves to the proper views. You can activate multiple constraints at once by passing an array containing the constraints to NSLayoutConstraint.activate() let label = UILabel(frame: CGRect.zero) … Read more
Summary: Disable scrolling of your text view, and don’t constraint its height. To do this programmatically, put the following code in viewDidLoad: let textView = UITextView(frame: .zero, textContainer: nil) textView.backgroundColor = .yellow // visual debugging textView.isScrollEnabled = false // causes expanding height view.addSubview(textView) // Auto Layout textView.translatesAutoresizingMaskIntoConstraints = false let safeArea = view.safeAreaLayoutGuide NSLayoutConstraint.activate([ textView.topAnchor.constraint(equalTo: … Read more
Yes, no issue when you change the constants. The thing here is that you have to set your constraint appropriately. Let’s consider an example. I have a UIView in Storyboard and I would like to change its width. Its default width is 1024. After some animation, We will change it’s width to 900. Follow steps … Read more
I just built this Category (https://github.com/damienromito/UIView-UpdateAutoLayoutConstraints) that update constrains when you want: //you can use tools to hide/show a uiview [myView1 hideByHeight:YES]; Or just do it to hide an UIView with autolayout: //Hide View [myView1 setConstraintConstant:0 forAttribute:NSLayoutAttributeHeight];
For others who come here: I got this error, because I added the constraints before I added the subviews to the hierarchy.
There is an arrow to the right of the constraint constant value. If you click on it, a menu pops out where you can choose what is it that you want to make your constraint relative to. If you choose ‘View’, than it will pin it to the top of the view.