iOS开发------手动约束布局出现NSAutoresizingMaskLayoutConstraint冲突(解决)

十分感谢一下博客让我解决了问题:
ios 约束冲突NSAutoresizingMaskLayoutConstraint

最近手写约束布局代码，适配不同屏幕的时候，出现了一个很奇怪的问题，不报错也不崩溃，最终的效果也是理想的，但就是出警告。原因是约束的大小不固定，需要根据屏幕的比例大小进行相应的变值。

程序是在iPhone5s上进行的开发，在那个时候是没有问题的，但运行在iPhone6s的时候，就会出现下面的警告，但运行的结果是理想中的效果:

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.
2016-05-05 14:10:20.354 IGO[5581:2754283] 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:0x13a093200 V:|-(10)-[UIImageView:0x13a0922d0]   (Names: '|':YBChildCell:0x13a08a8b0'YBChildObject' )>",
    "<NSLayoutConstraint:0x13a093280 V:[UIImageView:0x13a0922d0(82.0312)]>",
    "<NSLayoutConstraint:0x13a0932d0 V:[UIImageView:0x13a0922d0]-(10)-|   (Names: '|':YBChildCell:0x13a08a8b0'YBChildObject' )>",
    "<NSLayoutConstraint:0x13a09a2f0 'UIView-Encapsulated-Layout-Height' V:[YBChildCell:0x13a08a8b0'YBChildObject'(102)]>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x13a0932d0 V:[UIImageView:0x13a0922d0]-(10)-|   (Names: '|':YBChildCell:0x13a08a8b0'YBChildObject' )>

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.

大体的意思就是约束出现冲突，看到这个警告的第一个反应就是组件的translatesAutoresizingMaskIntoConstraints属性没有设置为false，但是检查过后，没有出现这个错误。

虽然不影响最终的布局，但每次一运行就爆出那么多的警告，着实觉得非常的不好，于是百度了一下，从而解决方法如下:

找到提示冲突的语句

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x13a0932d0 V:
[UIImageView:0x13a0922d0]-(10)-|   (Names:
 '|':YBChildCell:0x13a08a8b0'YBChildObject' )>

调整此约束的优先级，如下:

NSArray * ver1 = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|-10-[_headImageView(imageHeight)]-10-|"
                                                         options:0 metrics:metriceDictionary views:NSDictionaryOfVariableBindings(_headImageView)];

[ver1.firstObject setPriority:UILayoutPriorityDefaultHigh];//修改优先级

这样就不会出现那个警告了，具体原因，楼主表示真的不清楚，因为布局来看，是没有任何冲突的，如果有知道的人，也请告知一下…Thanks()