I have my UISearchBar being part of the navigation bar like:
let searchBar = UISearchBar()
//some more configuration to the search bar
.....
I believe in iOS 11 UISearchBar now has the height equals to 56, and UINavigationBar uses autolayout to fit its subviews hence it increases the height. If you still want to have UISearchBar as titleView as in pre-iOS 11, I found out the best way to do it is to embed UISearchBar in a custom view, and set this view's height to 44, and assign it to navigationItem.titleView
class SearchBarContainerView: UIView {
let searchBar: UISearchBar
init(customSearchBar: UISearchBar) {
searchBar = customSearchBar
super.init(frame: CGRect.zero)
addSubview(searchBar)
}
override convenience init(frame: CGRect) {
self.init(customSearchBar: UISearchBar())
self.frame = frame
}
required init?(coder aDecoder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
override func layoutSubviews() {
super.layoutSubviews()
searchBar.frame = bounds
}
}
class MyViewController: UIViewController {
func setupNavigationBar() {
let searchBar = UISearchBar()
let searchBarContainer = SearchBarContainerView(customSearchBar: searchBar)
searchBarContainer.frame = CGRect(x: 0, y: 0, width: view.frame.width, height: 44)
navigationItem.titleView = searchBarContainer
}
}