当我将translationsAutoresizingMaskIntoConstraints转换为false时，视图不显示

Question

I don't know if I'm missing out something, but when I comment this line

sideMenuView.view.translatesAutoresizingMaskIntoConstraints = false

then my side menu shows up but on the whole screen. I am setting its constraints programatically as:

let sideMenuView = UIStoryboard(name: "Main", bundle: nil).instantiateViewControllerWithIdentifier("sideMenuID") as! SideMenuViewController
var sideMenuLeftConstraint: NSLayoutConstraint?
var isShowingSideMenu = true
var blackMaskView = UIView(frame: CGRectZero)

override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view.

    // Add SideMenuViewController
    addChildViewController(sideMenuView)
    sideMenuView.delegate = self
    sideMenuView.didMoveToParentViewController(self)
    sideMenuView.view.translatesAutoresizingMaskIntoConstraints = false
    view.addSubview(sideMenuView.view)

    let topConstraint = NSLayoutConstraint(item: sideMenuView.view, attribute: NSLayoutAttribute.Top, relatedBy: NSLayoutRelation.Equal, toItem: view, attribute: NSLayoutAttribute.Top, multiplier: 1, constant: 0)
    let bottomConstraint = NSLayoutConstraint(item: sideMenuView.view, attribute: NSLayoutAttribute.Bottom, relatedBy: NSLayoutRelation.Equal, toItem: view, attribute: NSLayoutAttribute.Top, multiplier: 1, constant: 0)
    let widthConstraint = NSLayoutConstraint(item: sideMenuView.view, attribute: NSLayoutAttribute.Width, relatedBy: NSLayoutRelation.Equal, toItem: nil, attribute: NSLayoutAttribute.NotAnAttribute, multiplier: 1, constant: 200)
    sideMenuLeftConstraint = NSLayoutConstraint(item: sideMenuView.view, attribute: NSLayoutAttribute.Left, relatedBy: NSLayoutRelation.Equal, toItem: view, attribute: NSLayoutAttribute.Left, multiplier: 1, constant: -widthConstraint.constant)

    view.addConstraints([topConstraint, bottomConstraint, sideMenuLeftConstraint!, widthConstraint])

    toggleSideMenu()

}

func toggleSideMenu() {
    isShowingSideMenu = !isShowingSideMenu

    if(isShowingSideMenu) {
        // Hide Side Menu

        sideMenuLeftConstraint?.constant = -sideMenuView.view.bounds.size.width
        UIView.animateWithDuration(0.5, delay: 0.0, usingSpringWithDamping: 0.9, initialSpringVelocity: 0.5, options: UIViewAnimationOptions.CurveEaseInOut, animations: { () -> Void in
                          self.view.layoutIfNeeded()
                        },
            completion: {(completed) -> Void in
                          self.sideMenuView.view.hidden = true
                        })

        UIView.animateWithDuration(0.5, delay: 0.0, options: UIViewAnimationOptions.CurveEaseInOut,
            animations: { () -> Void in
                          self.view.layoutIfNeeded()
                          self.blackMaskView.alpha = 0.0
                        },
            completion: { (completed) -> Void in
                          self.blackMaskView.removeFromSuperview()
                        })

    } else {
        // Show Side Menu

        blackMaskView = UIView(frame: CGRectZero)
        blackMaskView.alpha = 0.0
        blackMaskView.translatesAutoresizingMaskIntoConstraints = false
        blackMaskView.backgroundColor = UIColor.blackColor()
        view.insertSubview(blackMaskView, belowSubview: sideMenuView.view)

        let topContraint = NSLayoutConstraint(item: blackMaskView, attribute: NSLayoutAttribute.Top, relatedBy: NSLayoutRelation.Equal, toItem: view, attribute: NSLayoutAttribute.Top, multiplier: 1, constant: 0)
        let bottomContraint = NSLayoutConstraint(item: blackMaskView, attribute: NSLayoutAttribute.Bottom, relatedBy: NSLayoutRelation.Equal, toItem: view, attribute: NSLayoutAttribute.Bottom, multiplier: 1, constant: 0)
        let leftContraint = NSLayoutConstraint(item: blackMaskView, attribute: NSLayoutAttribute.Leading, relatedBy: NSLayoutRelation.Equal, toItem: view, attribute: NSLayoutAttribute.Leading, multiplier: 1, constant: 0)
        let rightContraint = NSLayoutConstraint(item: blackMaskView, attribute: NSLayoutAttribute.Trailing, relatedBy: NSLayoutRelation.Equal, toItem: view, attribute: NSLayoutAttribute.Trailing, multiplier: 1, constant: 0)

        view.addConstraints([topContraint, bottomContraint, leftContraint, rightContraint])
        view.layoutIfNeeded()

        UIView.animateWithDuration(0.5, delay: 0.0, options: UIViewAnimationOptions.CurveEaseInOut,
            animations: { () -> Void in
                          self.view.layoutIfNeeded()
                          self.blackMaskView.alpha = 0.5
                        },
            completion: { (completed) -> Void in
                          let tapGesture = UITapGestureRecognizer(target: self, action: #selector(LoginUserMapView.tapGestureRecognized))
                          self.blackMaskView.addGestureRecognizer(tapGesture)
                        })

        sideMenuView.view.hidden = false
        sideMenuLeftConstraint?.constant = 0
        UIView.animateWithDuration(0.5, delay: 0.0, usingSpringWithDamping: 0.9, initialSpringVelocity: 0.5, options: UIViewAnimationOptions.CurveEaseInOut, animations: { () -> Void in
                          self.view.layoutIfNeeded()
                        },
            completion: {(completed) -> Void in
                        })

    }
}

func tapGestureRecognized() {
    toggleSideMenu()
}

@IBAction func sideMenuBtn(sender: AnyObject) {
    toggleSideMenu()
}

This is the code presenting a view controller "SideMenuViewController" as a side menu over another view controller. I want side menu to be presented but on half of my superview.

Answer 1

You need to fix your second constraint. From:

let bottomConstraint = NSLayoutConstraint(item: sideMenuView.view, attribute: NSLayoutAttribute.Bottom, relatedBy: NSLayoutRelation.Equal, toItem: view, attribute: NSLayoutAttribute.Top, multiplier: 1, constant: 0)

to:

let bottomConstraint = NSLayoutConstraint(item: sideMenuView.view, attribute: NSLayoutAttribute.Bottom, relatedBy: NSLayoutRelation.Equal, toItem: view, attribute: NSLayoutAttribute.Bottom, multiplier: 1, constant: 0)

At least that is what I think you intend. You might consider switching layout anchors unless you absolutely need to support iOS 8. Would shorten your constraints code to:

        sideMenuView.view.topAnchor.constraintEqualToAnchor(self.view.topAnchor).active = true
        sideMenuView.view.bottomAnchor.constraintEqualToAnchor(self.view.bottomAnchor).active = true
        let widthConstraint = sideMenuView.view.widthAnchor.constraintEqualToConstant(200)
        widthConstraint.active = true
        self.sideMenuLeftConstraint = sideMenuView.view.leadingAnchor.constraintEqualToAnchor(self.view.leadingAnchor, constant: -widthConstraint.constant)
        self.sideMenuLeftConstraint?.active = true

And is easier to follow IMHO.