How to add constraints programmatically using Swift

582,286

Solution 1

Do you plan to have a squared UIView of width: 100 and Height: 100 centered inside the UIView of an UIViewController? If so, you may try one of the 6 following Auto Layout styles (Swift 5 / iOS 12.2):


1. Using NSLayoutConstraint initializer

override func viewDidLoad() {
    let newView = UIView()
    newView.backgroundColor = UIColor.red
    view.addSubview(newView)

    newView.translatesAutoresizingMaskIntoConstraints = false
    let horizontalConstraint = NSLayoutConstraint(item: newView, attribute: NSLayoutConstraint.Attribute.centerX, relatedBy: NSLayoutConstraint.Relation.equal, toItem: view, attribute: NSLayoutConstraint.Attribute.centerX, multiplier: 1, constant: 0)
    let verticalConstraint = NSLayoutConstraint(item: newView, attribute: NSLayoutConstraint.Attribute.centerY, relatedBy: NSLayoutConstraint.Relation.equal, toItem: view, attribute: NSLayoutConstraint.Attribute.centerY, multiplier: 1, constant: 0)
    let widthConstraint = NSLayoutConstraint(item: newView, attribute: NSLayoutConstraint.Attribute.width, relatedBy: NSLayoutConstraint.Relation.equal, toItem: nil, attribute: NSLayoutConstraint.Attribute.notAnAttribute, multiplier: 1, constant: 100)
    let heightConstraint = NSLayoutConstraint(item: newView, attribute: NSLayoutConstraint.Attribute.height, relatedBy: NSLayoutConstraint.Relation.equal, toItem: nil, attribute: NSLayoutConstraint.Attribute.notAnAttribute, multiplier: 1, constant: 100)
    view.addConstraints([horizontalConstraint, verticalConstraint, widthConstraint, heightConstraint])
}
override func viewDidLoad() {
    let newView = UIView()
    newView.backgroundColor = UIColor.red
    view.addSubview(newView)

    newView.translatesAutoresizingMaskIntoConstraints = false
    let horizontalConstraint = NSLayoutConstraint(item: newView, attribute: NSLayoutConstraint.Attribute.centerX, relatedBy: NSLayoutConstraint.Relation.equal, toItem: view, attribute: NSLayoutConstraint.Attribute.centerX, multiplier: 1, constant: 0)
    let verticalConstraint = NSLayoutConstraint(item: newView, attribute: NSLayoutConstraint.Attribute.centerY, relatedBy: NSLayoutConstraint.Relation.equal, toItem: view, attribute: NSLayoutConstraint.Attribute.centerY, multiplier: 1, constant: 0)
    let widthConstraint = NSLayoutConstraint(item: newView, attribute: NSLayoutConstraint.Attribute.width, relatedBy: NSLayoutConstraint.Relation.equal, toItem: nil, attribute: NSLayoutConstraint.Attribute.notAnAttribute, multiplier: 1, constant: 100)
    let heightConstraint = NSLayoutConstraint(item: newView, attribute: NSLayoutConstraint.Attribute.height, relatedBy: NSLayoutConstraint.Relation.equal, toItem: nil, attribute: NSLayoutConstraint.Attribute.notAnAttribute, multiplier: 1, constant: 100)
    NSLayoutConstraint.activate([horizontalConstraint, verticalConstraint, widthConstraint, heightConstraint])
}
override func viewDidLoad() {
    let newView = UIView()
    newView.backgroundColor = UIColor.red
    view.addSubview(newView)

    newView.translatesAutoresizingMaskIntoConstraints = false
    NSLayoutConstraint(item: newView, attribute: NSLayoutConstraint.Attribute.centerX, relatedBy: NSLayoutConstraint.Relation.equal, toItem: view, attribute: NSLayoutConstraint.Attribute.centerX, multiplier: 1, constant: 0).isActive = true
    NSLayoutConstraint(item: newView, attribute: NSLayoutConstraint.Attribute.centerY, relatedBy: NSLayoutConstraint.Relation.equal, toItem: view, attribute: NSLayoutConstraint.Attribute.centerY, multiplier: 1, constant: 0).isActive = true
    NSLayoutConstraint(item: newView, attribute: NSLayoutConstraint.Attribute.width, relatedBy: NSLayoutConstraint.Relation.equal, toItem: nil, attribute: NSLayoutConstraint.Attribute.notAnAttribute, multiplier: 1, constant: 100).isActive = true
    NSLayoutConstraint(item: newView, attribute: NSLayoutConstraint.Attribute.height, relatedBy: NSLayoutConstraint.Relation.equal, toItem: nil, attribute: NSLayoutConstraint.Attribute.notAnAttribute, multiplier: 1, constant: 100).isActive = true
}

2. Using Visual Format Language

override func viewDidLoad() {
    let newView = UIView()
    newView.backgroundColor = UIColor.red
    view.addSubview(newView)

    newView.translatesAutoresizingMaskIntoConstraints = false
    let views = ["view": view!, "newView": newView]
    let horizontalConstraints = NSLayoutConstraint.constraints(withVisualFormat: "H:[view]-(<=0)-[newView(100)]", options: NSLayoutConstraint.FormatOptions.alignAllCenterY, metrics: nil, views: views)
    let verticalConstraints = NSLayoutConstraint.constraints(withVisualFormat: "V:[view]-(<=0)-[newView(100)]", options: NSLayoutConstraint.FormatOptions.alignAllCenterX, metrics: nil, views: views)
    view.addConstraints(horizontalConstraints)
    view.addConstraints(verticalConstraints)
}
override func viewDidLoad() {
    let newView = UIView()
    newView.backgroundColor = UIColor.red
    view.addSubview(newView)

    newView.translatesAutoresizingMaskIntoConstraints = false
    let views = ["view": view!, "newView": newView]
    let horizontalConstraints = NSLayoutConstraint.constraints(withVisualFormat: "H:[view]-(<=0)-[newView(100)]", options: NSLayoutConstraint.FormatOptions.alignAllCenterY, metrics: nil, views: views)
    let verticalConstraints = NSLayoutConstraint.constraints(withVisualFormat: "V:[view]-(<=0)-[newView(100)]", options: NSLayoutConstraint.FormatOptions.alignAllCenterX, metrics: nil, views: views)
    NSLayoutConstraint.activate(horizontalConstraints)
    NSLayoutConstraint.activate(verticalConstraints)
}

3. Using a mix of NSLayoutConstraint initializer and Visual Format Language

override func viewDidLoad() {
    let newView = UIView()
    newView.backgroundColor = UIColor.red
    view.addSubview(newView)

    newView.translatesAutoresizingMaskIntoConstraints = false
    let views = ["newView": newView]
    let widthConstraints = NSLayoutConstraint.constraints(withVisualFormat: "H:[newView(100)]", options: NSLayoutConstraint.FormatOptions(rawValue: 0), metrics: nil, views: views)
    let heightConstraints = NSLayoutConstraint.constraints(withVisualFormat: "V:[newView(100)]", options: NSLayoutConstraint.FormatOptions(rawValue: 0), metrics: nil, views: views)
    let horizontalConstraint = NSLayoutConstraint(item: newView, attribute: NSLayoutConstraint.Attribute.centerX, relatedBy: NSLayoutConstraint.Relation.equal, toItem: view, attribute: NSLayoutConstraint.Attribute.centerX, multiplier: 1, constant: 0)
    let verticalConstraint = NSLayoutConstraint(item: newView, attribute: NSLayoutConstraint.Attribute.centerY, relatedBy: NSLayoutConstraint.Relation.equal, toItem: view, attribute: NSLayoutConstraint.Attribute.centerY, multiplier: 1, constant: 0)
    view.addConstraints(widthConstraints)
    view.addConstraints(heightConstraints)
    view.addConstraints([horizontalConstraint, verticalConstraint])
}
override func viewDidLoad() {
    let newView = UIView()
    newView.backgroundColor = UIColor.red
    view.addSubview(newView)

    newView.translatesAutoresizingMaskIntoConstraints = false
    let views = ["newView": newView]
    let widthConstraints = NSLayoutConstraint.constraints(withVisualFormat: "H:[newView(100)]", options: NSLayoutConstraint.FormatOptions(rawValue: 0), metrics: nil, views: views)
    let heightConstraints = NSLayoutConstraint.constraints(withVisualFormat: "V:[newView(100)]", options: NSLayoutConstraint.FormatOptions(rawValue: 0), metrics: nil, views: views)
    let horizontalConstraint = NSLayoutConstraint(item: newView, attribute: NSLayoutConstraint.Attribute.centerX, relatedBy: NSLayoutConstraint.Relation.equal, toItem: view, attribute: NSLayoutConstraint.Attribute.centerX, multiplier: 1, constant: 0)
    let verticalConstraint = NSLayoutConstraint(item: newView, attribute: NSLayoutConstraint.Attribute.centerY, relatedBy: NSLayoutConstraint.Relation.equal, toItem: view, attribute: NSLayoutConstraint.Attribute.centerY, multiplier: 1, constant: 0)
    NSLayoutConstraint.activate(widthConstraints)
    NSLayoutConstraint.activate(heightConstraints)
    NSLayoutConstraint.activate([horizontalConstraint, verticalConstraint])
}
override func viewDidLoad() {
    let newView = UIView()
    newView.backgroundColor = UIColor.red
    view.addSubview(newView)

    newView.translatesAutoresizingMaskIntoConstraints = false
    let views = ["newView": newView]
    let widthConstraints = NSLayoutConstraint.constraints(withVisualFormat: "H:[newView(100)]", options: NSLayoutConstraint.FormatOptions(rawValue: 0), metrics: nil, views: views)
    let heightConstraints = NSLayoutConstraint.constraints(withVisualFormat: "V:[newView(100)]", options: NSLayoutConstraint.FormatOptions(rawValue: 0), metrics: nil, views: views)
    NSLayoutConstraint.activate(widthConstraints)
    NSLayoutConstraint.activate(heightConstraints)
    NSLayoutConstraint(item: newView, attribute: NSLayoutConstraint.Attribute.centerX, relatedBy: NSLayoutConstraint.Relation.equal, toItem: view, attribute: NSLayoutConstraint.Attribute.centerX, multiplier: 1, constant: 0).isActive = true
    NSLayoutConstraint(item: newView, attribute: NSLayoutConstraint.Attribute.centerY, relatedBy: NSLayoutConstraint.Relation.equal, toItem: view, attribute: NSLayoutConstraint.Attribute.centerY, multiplier: 1, constant: 0).isActive = true
}

4. Using UIView.AutoresizingMask

Note: Springs and Struts will be translated into corresponding auto layout constraints at runtime.

override func viewDidLoad() {
    let newView = UIView(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
    newView.backgroundColor = UIColor.red
    view.addSubview(newView)

    newView.translatesAutoresizingMaskIntoConstraints = true
    newView.center = CGPoint(x: view.bounds.midX, y: view.bounds.midY)
    newView.autoresizingMask = [UIView.AutoresizingMask.flexibleLeftMargin, UIView.AutoresizingMask.flexibleRightMargin, UIView.AutoresizingMask.flexibleTopMargin, UIView.AutoresizingMask.flexibleBottomMargin]
}

5. Using NSLayoutAnchor

override func viewDidLoad() {
    let newView = UIView()
    newView.backgroundColor = UIColor.red
    view.addSubview(newView)
    
    newView.translatesAutoresizingMaskIntoConstraints = false
    let horizontalConstraint = newView.centerXAnchor.constraint(equalTo: view.centerXAnchor)
    let verticalConstraint = newView.centerYAnchor.constraint(equalTo: view.centerYAnchor)
    let widthConstraint = newView.widthAnchor.constraint(equalToConstant: 100)
    let heightConstraint = newView.heightAnchor.constraint(equalToConstant: 100)
    view.addConstraints([horizontalConstraint, verticalConstraint, widthConstraint, heightConstraint])
}
override func viewDidLoad() {
    let newView = UIView()
    newView.backgroundColor = UIColor.red
    view.addSubview(newView)
    
    newView.translatesAutoresizingMaskIntoConstraints = false
    let horizontalConstraint = newView.centerXAnchor.constraint(equalTo: view.centerXAnchor)
    let verticalConstraint = newView.centerYAnchor.constraint(equalTo: view.centerYAnchor)
    let widthConstraint = newView.widthAnchor.constraint(equalToConstant: 100)
    let heightConstraint = newView.heightAnchor.constraint(equalToConstant: 100)
    NSLayoutConstraint.activate([horizontalConstraint, verticalConstraint, widthConstraint, heightConstraint])
}
override func viewDidLoad() {
    let newView = UIView()
    newView.backgroundColor = UIColor.red
    view.addSubview(newView)
    
    newView.translatesAutoresizingMaskIntoConstraints = false
    newView.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
    newView.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
    newView.widthAnchor.constraint(equalToConstant: 100).isActive = true
    newView.heightAnchor.constraint(equalToConstant: 100).isActive = true
}

6. Using intrinsicContentSize and NSLayoutAnchor

import UIKit

class CustomView: UIView {
    
    override var intrinsicContentSize: CGSize {
        return CGSize(width: 100, height: 100)
    }
    
}

class ViewController: UIViewController {
    
    override func viewDidLoad() {
        let newView = CustomView()
        newView.backgroundColor = UIColor.red
        view.addSubview(newView)
        
        newView.translatesAutoresizingMaskIntoConstraints = false
        let horizontalConstraint = newView.centerXAnchor.constraint(equalTo: view.centerXAnchor)
        let verticalConstraint = newView.centerYAnchor.constraint(equalTo: view.centerYAnchor)
        NSLayoutConstraint.activate([horizontalConstraint, verticalConstraint])
    }
    
}

Result:

enter image description here

Solution 2

It helps me to learn visually, so this is a supplemental answer.

Boilerplate code

override func viewDidLoad() {
    super.viewDidLoad()

    let myView = UIView()
    myView.backgroundColor = UIColor.blue
    myView.translatesAutoresizingMaskIntoConstraints = false
    view.addSubview(myView)

    // Add constraints code here
    // ...
}

Each of the following examples are independent of the others.

Pin left edge

myView.leading = leadingMargin + 20

enter image description here

Method 1: Anchor Style

let margins = view.layoutMarginsGuide
myView.leadingAnchor.constraint(equalTo: margins.leadingAnchor, constant: 20).isActive = true
  • In addition to leadingAnchor, there is also trailingAnchor, topAnchor, and bottomAnchor.

Method 2: NSLayoutConstraint Style

NSLayoutConstraint(item: myView, attribute: NSLayoutAttribute.leading, relatedBy: NSLayoutRelation.equal, toItem: view, attribute: NSLayoutAttribute.leadingMargin, multiplier: 1.0, constant: 20.0).isActive = true
  • In addition to .leading there is also .trailing, .top, and .bottom.
  • In addition to .leadingMargin there is also .trailingMargin, .topMargin, and .bottomMargin.

Set Width and Height

width = 200
height = 100

enter image description here

Method 1: Anchor Style

myView.widthAnchor.constraint(equalToConstant: 200).isActive = true
myView.heightAnchor.constraint(equalToConstant: 100).isActive = true

Method 2: NSLayoutConstraint Style

NSLayoutConstraint(item: myView, attribute: NSLayoutAttribute.width, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: 200).isActive = true
NSLayoutConstraint(item: myView, attribute: NSLayoutAttribute.height, relatedBy: NSLayoutRelation.equal, toItem: nil, attribute: NSLayoutAttribute.notAnAttribute, multiplier: 1, constant: 100).isActive = true

Center in container

myView.centerX = centerX
myView.centerY = centerY

enter image description here

Method 1: Anchor Style

myView.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
myView.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true

Method 2: NSLayoutConstraint Style

NSLayoutConstraint(item: myView, attribute: NSLayoutAttribute.centerX, relatedBy: NSLayoutRelation.equal, toItem: view, attribute: NSLayoutAttribute.centerX, multiplier: 1, constant: 0).isActive = true
NSLayoutConstraint(item: myView, attribute: NSLayoutAttribute.centerY, relatedBy: NSLayoutRelation.equal, toItem: view, attribute: NSLayoutAttribute.centerY, multiplier: 1, constant: 0).isActive = true

Notes

  • Anchor style is the preferred method over NSLayoutConstraint Style, however it is only available from iOS 9, so if you are supporting iOS 8 then you should still use NSLayoutConstraint Style.
  • The examples above showed just the one or two constraints that were being focused on. However, in order to properly place myView in my test project I needed to have four constraints.

Further Reading

Solution 3

If you want to fill your super view then I suggest the swifty way:

    view.translatesAutoresizingMaskIntoConstraints = false
    let attributes: [NSLayoutAttribute] = [.top, .bottom, .right, .left]
    NSLayoutConstraint.activate(attributes.map {
        NSLayoutConstraint(item: view, attribute: $0, relatedBy: .equal, toItem: view.superview, attribute: $0, multiplier: 1, constant: 0)
    })

Other wise if you need non equal constraints check out NSLayoutAnchor as of iOS 9. Its often much easier to read that using NSLayoutConstraint directly:

    view.translatesAutoresizingMaskIntoConstraints = false
    view.topAnchor.constraint(equalTo: view.superview!.topAnchor).isActive = true
    view.bottomAnchor.constraint(equalTo: view.superview!.bottomAnchor).isActive = true
    view.leadingAnchor.constraint(equalTo: view.superview!.leadingAnchor, constant: 10).isActive = true
    view.trailingAnchor.constraint(equalTo: view.superview!.trailingAnchor, constant: 10).isActive = true

Solution 4

Constraints for multiple views in playground.

swift 3+

  var yellowView: UIView!
    var redView: UIView!

    override func loadView() {

        // UI

        let view = UIView()
        view.backgroundColor = .white

        yellowView = UIView()
        yellowView.backgroundColor = .yellow
        view.addSubview(yellowView)

        redView = UIView()
        redView.backgroundColor = .red
        view.addSubview(redView)

        // Layout
        redView.translatesAutoresizingMaskIntoConstraints = false
        yellowView.translatesAutoresizingMaskIntoConstraints = false
        NSLayoutConstraint.activate([
            yellowView.topAnchor.constraint(equalTo: view.topAnchor, constant: 20),
            yellowView.leadingAnchor.constraint(equalTo: view.leadingAnchor, constant: 20),
            yellowView.widthAnchor.constraint(equalToConstant: 80),
            yellowView.heightAnchor.constraint(equalToConstant: 80),

            redView.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: -20),
            redView.trailingAnchor.constraint(equalTo: view.trailingAnchor,constant: -20),
            redView.widthAnchor.constraint(equalToConstant: 80),
            redView.heightAnchor.constraint(equalToConstant: 80)
            ])

        self.view = view
    }

In my opinion xcode playground is the best place for learning adding constraints programmatically.

Playground image

Solution 5

We can easily do this with in swift 5.1

setup 1

  • subview align to view center
  • subview width height set using float

    view.addSubview(myView1)
    myView1.translatesAutoresizingMaskIntoConstraints = false
    NSLayoutConstraint.activate([
        myView1.centerXAnchor.constraint(equalTo: view.centerXAnchor),
        myView1.centerYAnchor.constraint(equalTo: view.centerYAnchor),
        myView1.widthAnchor.constraint(equalToConstant: 100),
        myView1.heightAnchor.constraint(equalToConstant: 100),
    ])
    

setup 2

  • subview align to view leading and top anchor
  • subview width set using view width height

        view.addSubview(myView2)
        myView2.translatesAutoresizingMaskIntoConstraints = false
    
        NSLayoutConstraint.activate([
            myView2.leadingAnchor.constraint(equalTo: view.leadingAnchor,constant: 16),
            myView2.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor,constant: 16),
            myView2.widthAnchor.constraint(equalTo: view.widthAnchor, multiplier: 0.3),
            myView2.heightAnchor.constraint(equalTo: view.heightAnchor, multiplier: 0.3)
        ])
    

Result

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Sara Canducci
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Sara Canducci

Nothing much to say about me...creative arts are my life! Have questions about computer programming, photography, video making or editing? Just ask, I'll be glad to answer! :)

Updated on February 16, 2021

Comments

  • Sara Canducci
    Sara Canducci about 3 years

    I'm trying to figure this out since last week without going any step further. Ok, so I need to apply some constraints programmatically in Swift to a UIView using this code:

    var new_view:UIView! = UIView(frame: CGRectMake(0, 0, 100, 100));
    new_view.backgroundColor = UIColor.redColor();
    view.addSubview(new_view);
    
    var constX:NSLayoutConstraint = NSLayoutConstraint(item: new_view, attribute: NSLayoutAttribute.CenterX, relatedBy: NSLayoutRelation.Equal, toItem: self.view, attribute: NSLayoutAttribute.CenterX, multiplier: 1, constant: 0);
    self.view.addConstraint(constX);
    
    var constY:NSLayoutConstraint = NSLayoutConstraint(item: new_view, attribute: NSLayoutAttribute.CenterY, relatedBy: NSLayoutRelation.Equal, toItem: self.view, attribute: NSLayoutAttribute.CenterY, multiplier: 1, constant: 0);
    self.view.addConstraint(constY);
    
    var constW:NSLayoutConstraint = NSLayoutConstraint(item: new_view, attribute: NSLayoutAttribute.Width, relatedBy: NSLayoutRelation.Equal, toItem: new_view, attribute: NSLayoutAttribute.Width, multiplier: 1, constant: 0);
    self.view.addConstraint(constW);
    
    var constH:NSLayoutConstraint = NSLayoutConstraint(item: new_view, attribute: NSLayoutAttribute.Height, relatedBy: NSLayoutRelation.Equal, toItem: new_view, attribute: NSLayoutAttribute.Height, multiplier: 1, constant: 0);
    self.view.addConstraint(constH);
    

    But Xcode returns this weird output:

    2014-10-03 09:48:12.657 Test[35088:2454916] Unable to simultaneously satisfy constraints.  Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; (2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints) 
    (
    "<NSLayoutConstraint:0x7fa4ea446830 UIView:0x7fa4ea429290.centerX == UIView:0x7fa4ea4470f0.centerX>",
    "<NSAutoresizingMaskLayoutConstraint:0x7fa4ea4516c0 h=--& v=--& UIView:0x7fa4ea429290.midX == + 50>",
    "<NSLayoutConstraint:0x7fa4ea452830 'UIView-Encapsulated-Layout-Width' H:[UIView:0x7fa4ea4470f0(375)]>",
    "<NSAutoresizingMaskLayoutConstraint:0x7fa4ea446db0 h=-&- v=-&- 'UIView-Encapsulated-Layout-Left' H:|-(0)-[UIView:0x7fa4ea4470f0]   (Names: '|':UIWindow:0x7fa4ea444b20 )>"
    )
    
    Will attempt to recover by breaking constraint <NSLayoutConstraint:0x7fa4ea446830 UIView:0x7fa4ea429290.centerX == UIView:0x7fa4ea4470f0.centerX>
    
    Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger. The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in
    <UIKit/UIView.h> may also be helpful.
    
    2014-10-03 09:48:12.658 Test[35088:2454916] Unable to simultaneously satisfy constraints.  Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; (2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints)
    (
    "<NSLayoutConstraint:0x7fa4ea44d160 UIView:0x7fa4ea429290.centerY == UIView:0x7fa4ea4470f0.centerY>",
    "<NSAutoresizingMaskLayoutConstraint:0x7fa4ea451b30 h=--& v=--& UIView:0x7fa4ea429290.midY == + 50>",
    "<NSLayoutConstraint:0x7fa4ea44cf00 'UIView-Encapsulated-Layout-Height' V:[UIView:0x7fa4ea4470f0(667)]>",
    "<NSAutoresizingMaskLayoutConstraint:0x7fa4ea452700 h=-&- v=-&- 'UIView-Encapsulated-Layout-Top' V:|-(0)-[UIView:0x7fa4ea4470f0]  (Names: '|':UIWindow:0x7fa4ea444b20 )>"
    )
    
    Will attempt to recover by breaking constraint <NSLayoutConstraint:0x7fa4ea44d160 UIView:0x7fa4ea429290.centerY == UIView:0x7fa4ea4470f0.centerY>
    
    Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger. The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.
    

    Can you help me? Thanks a lot