使用Masonry时出现 [LayoutConstraints] Unable to simultaneously satisfy constraints

使用Masonry时出现

[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. 

至于解决方案，就是对view内部使用Masonry布局的空间添加布局优先级，就可以移除这些警告了。

例如：

[self.backgroundImageView mas_makeConstraints:^(MASConstraintMaker*make){make.edges.equalTo(self);}];

修改为：

[self.backgroundImageView mas_makeConstraints:^(MASConstraintMaker*make){make.edges.equalTo(self).priorityHigh();}];