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iosautolayoutuilabel

ios correct way to use constraintLessThanOrEqualToSystemSpacingAfter for trailingAnchor

I'd like to programmatically layout a UILabel that should fit the width of the screen, with the system spacing as left and right insets. Here's my code:

statusLabel.font = UIFont.systemFont(ofSize: UIFont.smallSystemFontSize)
statusLabel.numberOfLines = 0
statusLabel.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(statusLabel)

statusLabel.topAnchor.constraint(equalTo: otherView.bottomAnchor, constant: 0),
statusLabel.leadingAnchor.constraintEqualToSystemSpacingAfter(view.safeAreaLayoutGuide.leadingAnchor, multiplier: 1),
statusLabel.trailingAnchor.constraintLessThanOrEqualToSystemSpacingAfter(view.safeAreaLayoutGuide.trailingAnchor, multiplier: 1),
statusLabel.bottomAnchor.constraint(equalTo: someOtherView.topAnchor, constant: 0)

Here is the result:

enter image description here

the label is laid out using the system spacing as the left inset, as intended, but its trailingAnchor seems to be equal to the superview's trailingAnchor rather than adding a system spacing between the two.

I've tried using constraintEqualToSystemSpacingAfter and constraintGreaterThanOrEqualToSystemSpacingAfter but got the same results.

Any ideas on how to get the system spacing between the label and its superview's trailing anchors?

Solution

  • Reverse the order Like this

    view.safeAreaLayoutGuide.trailingAnchor.constraintEqualToSystemSpacingAfter(statusLabel.trailingAnchor, multiplier: 1).isActive = true

    view first & statusLabel next.