How to programmatically add an InputAccessoryView with Autolayout?

Question

I am trying to add a UIView with "Done" button as an input accessory view to the text field.

        let view = UIView()
        let doneButton = UIButton(type: .Custom)
        doneButton.setTitle("Done", forState: .Normal)
        doneButton.translatesAutoresizingMaskIntoConstraints = false
        view.addSubview(doneButton)
        view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("H:[button]-|", options: NSLayoutFormatOptions.DirectionLeadingToTrailing, metrics: nil, views: ["button":doneButton]))
        view.addConstraints(NSLayoutConstraint.constraintsWithVisualFormat("V:|[button]|", options: NSLayoutFormatOptions.DirectionLeadingToTrailing, metrics: nil, views: ["button":doneButton]))
        view.addConstraint(NSLayoutConstraint(item: view, attribute: NSLayoutAttribute.Height, relatedBy: NSLayoutRelation.Equal, toItem: doneButton, attribute: NSLayoutAttribute.Height, multiplier: 1, constant: 0)) // Even this does not work
        self.emailTextField.inputAccessoryView = view

But however I cannot see the views height being set nor the buttons in the View Hierarchy debugger/inspector in Xcode.

But if I add a view by setting its frame I can see the view being added. Also I tried setting height constraint forcibly to a constant 21 and it broke some other constraints which I had not added _UIKBAutolayoutHeightConstraint

"<NSLayoutConstraint:0x7fa3c962be50 UIView:0x7fa3c963bf60.height == UIButton:0x7fa3c963c0d0.height + 21>",
    "<NSLayoutConstraint:0x7fa3c95e0a90 '_UIKBAutolayoutHeightConstraint' V:[UIView:0x7fa3c963bf60(0)]>"

Any one faced this issue before ?

Widescreen

Why do you want to do button and view setup in the code? You could do it in the interface builder. – Maternity

@Maternity I am just doing everything in code instead of building views. So even this is added programmatically. – Widescreen

Answer 1

Swift 3+

1. You need to specify size of toolbar view in first line.

2. Don't use 'view' as variable in viewcontroller class since it creates confusion vs self.view

   override func viewDidLoad() {
       super.viewDidLoad()
       let toolBar = UIView(frame: CGRect(x: 0, y: 0, width: view.bounds.width, height: 50))
       toolBar.backgroundColor = .gray
       let doneButton = UIButton(type: .custom)
       doneButton.setTitle("Done", for: .normal)
       doneButton.translatesAutoresizingMaskIntoConstraints = false
       toolBar.addSubview(doneButton)
       toolBar.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "H:[button]-|", 
                                                             options: .directionLeadingToTrailing, 
                                                             metrics: nil, 
                                                             views: ["button":doneButton]))
       toolBar.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "V:|[button]|", 
                                                             options: .directionLeadingToTrailing, 
                                                             metrics: nil, 
                                                             views: ["button":doneButton]))
       self.emailTextField.inputAccessoryView = toolBar 
   }
   

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