CODEWITHSUNDEEP
iosswift
user0246
user0246

Reputation: 65

How to resolve Autolayout issue in Swift 3?

Here I had used activity indicator programmatically and given constraints programmatically but got crashed at the NSLayoutConstraint returning an error can anyone help me how to resolve this ?

here is my error in console

2017-11-04 16:46:41.657 Ecommerce[2744:71044] *** Terminating app due to uncaught exception 'NSGenericException', reason: 'Unable to activate constraint with anchors and because they have no common ancestor. Does the constraint or its anchors reference items in different view hierarchies? That's illegal.'

func showActivityIndicator(uiView: UIView) {
    container.frame = uiView.frame
    container.center = uiView.center
    container.backgroundColor = UIColorFromHex(rgbValue: 0xffffff, alpha: 0.3)

    loadingView.frame = CGRect(x: 0, y: 0, width: 80, height: 80)
    loadingView.center = uiView.center
    loadingView.backgroundColor = UIColorFromHex(rgbValue: 0x444444, alpha: 0.7)
    loadingView.clipsToBounds = true
    loadingView.layer.cornerRadius = 10

    customActivityIndicator.frame = CGRect(x: 0, y: 0, width: 40, height: 40)
    customActivityIndicator.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.whiteLarge
    customActivityIndicator.center = CGPoint(x: loadingView.frame.size.width / 2, y: loadingView.frame.size.height / 2)

    loadingView.addSubview(customActivityIndicator)
    view.isUserInteractionEnabled = false
    container.addSubview(loadingView)
    container.translatesAutoresizingMaskIntoConstraints = false
    NSLayoutConstraint(
        item: container,
        attribute: .centerX,
        relatedBy: .equal,
        toItem: view,
        attribute: .centerX,
        multiplier: 1.0,
        constant: 0.0
        ).isActive = true

    NSLayoutConstraint(
        item: container,
        attribute: .centerY,
        relatedBy: .equal,
        toItem: view,
        attribute: .centerY,
        multiplier: 1.0, 
        constant: 0.0
        ).isActive = true
    NSLayoutConstraint(item: container, attribute: .width, relatedBy: .equal, toItem: contentView, attribute: .width, multiplier: 1, constant: view.frame.size.width / 2).isActive = true
    NSLayoutConstraint(item: container, attribute: .height, relatedBy: .equal, toItem: contentView, attribute: .height, multiplier: 1, constant: view.frame.size.height / 2).isActive = true
    contentView.addSubview(container)
    customActivityIndicator.startAnimating()
}

Upvotes: 1

Views: 194

Answers (1)

vacawama
vacawama

Reputation: 154731

Add your subviews before you create the constraints.

Move this line:

contentView.addSubview(container)

to before the creation/activation of the constraints.

Upvotes: 1

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