How to get safe area frame of programmatically created ViewController? - ios

Question

Note : Not created ViewController in storyboard
I created ViewController programmatically after giving support for safe guard now my problem is that how i can got his height?
I try following thing but no luck
let guide = view.safeAreaLayoutGuide
let height = guide.layoutFrame.size.height
print("\(height)")
print("\(self.view.frame.height)")
height = 812.0, self.view height = 812.0
Is there any other way?

Answer 1

A safeAreaLayoutGuide, which is iOS 11+, is meant for auto layout and to try to get a frame is close to trying to make orange juice from a lemon.
If what you want is to find out is what you can safely use for a frame, maybe try something like this:
Create a transparent view:
let mySafeView = UIView()
override func viewDidLoad() {
super.viewDidLoad()
mySafeView.backgroundColor = UIColor.clear
mySafeView.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(mySafeView)
// if needed, send this view to the back of the hierarchy
view.sendSubview(toBack: mySafeView)
}
Next, in your constraint-building code attach it to the true anchors:
// create generic layout guides
let layoutGuideTop = UILayoutGuide()
view.addLayoutGuide(layoutGuideTop)
let layoutGuideBottom = UILayoutGuide()
view.addLayoutGuide(layoutGuideBottom)
let margins = view.layoutMarginsGuide
view.addLayoutGuide(margins)
// get correct top/bottom margins based on iOS version
if #available(iOS 11, *) {
let guide = view.safeAreaLayoutGuide
layoutGuideTop.topAnchor.constraintEqualToSystemSpacingBelow(guide.topAnchor, multiplier: 1.0).isActive = true
layoutGuideBottom.bottomAnchor.constraintEqualToSystemSpacingBelow(guide.bottomAnchor, multiplier: 1.0).isActive = true
} else {
layoutGuideTop.topAnchor.constraint(equalTo: topLayoutGuide.bottomAnchor).isActive = true
layoutGuideBottom.bottomAnchor.constraint(equalTo: bottomLayoutGuide.topAnchor).isActive = true
}
mySafeView.topAnchor.constraint(equalTo: layoutGuideTop.topAnchor).isActive = true
mySafeView.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
mySafeView.bottomAnchor.constraint(equalTo: layoutGuideBottom.bottomAnchor).isActive = true
mySafeView.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
Finally, get the frame size:
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
print(mySafeView.frame)
}
On an iPhone 6 plus running iOS 11.1 you get:
(0.0, 28.0, 414.0, 716.0)
On an iPhone 6 plus running iOS 9.0 you get:
(0.0, 20.0, 414.0, 716.0)

Answer 2

First off you can't do it in the viewDidLoad. You have to wait till viewDidLayoutSubviews
override func viewDidLayoutSubviews() {
super.viewDidLayoutSubviews()
myGlobalVars.sceneRect = view.frame
if #available(iOS 11.0, *) {
myGlobalVars.topSafeArea = view.safeAreaInsets.top
myGlobalVars.bottomSafeArea = view.safeAreaInsets.bottom
} else {
myGlobalVars.topSafeArea = topLayoutGuide.length
myGlobalVars.bottomSafeArea = bottomLayoutGuide.length
}
}