利用约束优先级解决Autolayout冲突

2018-06-26 15:13:08.067547 xxxx[302:38207] [LayoutConstraints] Unable to simultaneously satisfy constraints.
Probably at least one of the constraints in the following list is one you don't want. 
Try this: 
    (1) look at each constraint and try to figure out which you don't expect; 
    (2) find the code that added the unwanted constraint or constraints and fix it. 
    
    ...
    
Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.

NSLayoutConstraint.autoSetPriority(900) {
        [weak self] in
        self?.nameBtn.autoPinEdge(toSuperviewEdge: .trailing, withInset: 15)
    }