问iOS 11：“无法同时满足约束”

EN

2018-02-09 11:19:42.130595+0100 FoodTracker[7439:80369] [MC] Lazy loading NSBundle MobileCoreServices.framework  
2018-02-09 11:19:42.131628+0100 FoodTracker[7439:80369] [MC] Loaded MobileCoreServices.framework  
2018-02-09 11:19:42.165143+0100 FoodTracker[7439:80369] [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.  
(  
    "<NSLayoutConstraint:0x60400028a3c0 UIButton:0x7f8a0bd0e330.width == 44   (active)>",  
    "<NSLayoutConstraint:0x60400028cda0 'UISV-canvas-connection' FoodTracker.RatingControl:0x7f8a0bd08890.leading == UIButton:0x7f8a0bd0e330.leading   (active)>",  
    "<NSLayoutConstraint:0x60400028ce40 'UISV-canvas-connection' H:[UIButton:0x7f8a0bd0e330]-(0)-|   (active, names: '|':FoodTracker.RatingControl:0x7f8a0bd08890 )>",  
    "<NSLayoutConstraint:0x60400028c940 'UIView-Encapsulated-Layout-Width' FoodTracker.RatingControl:0x7f8a0bd08890.width == 200   (active)>"  
)  

Will attempt to recover by breaking constraint  
<NSLayoutConstraint:0x60400028a3c0 UIButton:0x7f8a0bd0e330.width == 44   (active)>  

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.  
2018-02-09 11:19:42.165949+0100 FoodTracker[7439:80369] [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.  
(  
    "<NSLayoutConstraint:0x60400028a370 UIButton:0x7f8a0bd0e330.height == 44   (active)>",  
    "<NSLayoutConstraint:0x60400028a320 'UISV-canvas-connection' FoodTracker.RatingControl:0x7f8a0bd08890.top == UIButton:0x7f8a0bd0e330.top   (active)>",  
    "<NSLayoutConstraint:0x60400028cf30 'UISV-canvas-connection' V:[UIButton:0x7f8a0bd0e330]-(0)-|   (active, names: '|':FoodTracker.RatingControl:0x7f8a0bd08890 )>",  
    "<NSLayoutConstraint:0x60400028c990 'UIView-Encapsulated-Layout-Height' FoodTracker.RatingControl:0x7f8a0bd08890.height == 110   (active)>"  
)  

Will attempt to recover by breaking constraint  
<NSLayoutConstraint:0x60400028a370 UIButton:0x7f8a0bd0e330.height == 44   (active)>  

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.  

// Add constraints  
button.translatesAutoresizingMaskIntoConstraints = false  
button.heightAnchor.constraint(equalToConstant: 44.0).isActive = true  
button.widthAnchor.constraint(equalToConstant: 44.0).isActive = true