How to debug Auto Layout

[onmyway133]

hasAmbiguousLayout

Returns whether the constraints impacting the layout of the view incompletely specify the location of the view.

exerciseAmbiguityInLayout

This method randomly changes the frame of a view with an ambiguous layout between its different valid values, causing the view to move in the interface. This makes it easy to visually identify what the valid frames are and may enable the developer to discern what constraints need to be added to the layout to fully specify a location for the view.

_autolayoutTrace

This returns a string describing the whole view tree which tells you when a view has an ambiguous layout.

NSLayoutConstraint identifier

The name that identifies the constraint.

UIViewAlertForUnsatisfiableConstraints

• https://medium.com/@karthikkeyan/debugging-uiviewalertforunsatisfiableconstraints-47697696c7c

DETECTED_MISSING_CONSTRAINTS

https://forums.developer.apple.com/thread/63811

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Read more

• Debugging Tricks and Tips
• Advanced Auto Layout Toolbox
• Mysteries of Auto Layout, Part 2