[label1 setContentHuggingPriority:UILayoutPriorityRequired
forAxis:UILayoutConstraintAxisHorizontal];
[label2 setContentHuggingPriority:UILayoutPriorityDefaultLow
forAxis:UILayoutConstraintAxisHorizontal];
[label1 setContentCompressionResistancePriority:UILayoutPriorityDefaultLow
forAxis:UILayoutConstraintAxisVertical];
[label2 setContentCompressionResistancePriority:UILayoutPriorityRequired
forAxis:UILayoutConstraintAxisVertical];
原文:https://www.cnblogs.com/kingstudy/p/11474200.html