autolayout--Precedence of constraints

When you use AutoLayout to constrain, you may want to change the constraint on a view halfway

A set of constraints that can only change the constant parameter during code execution and that the constrained object and reference scale cannot be changed

Now I know a new skill: change a constraint by changing the precedence of a constraint

When priority is 1000, it is not possible to change the precedence, so the xib can always lower the priority, then add similar constraints, in the code by adjusting the priority to determine exactly which constraint to use

Demo>>

autolayout--Precedence of constraints