iOS Masonry 設置布局優先級。

Masonry 中設置布局優先級需要使用系統方法：

 

設置抗拉伸性。值越低越容易被拉伸

- (void)setContentHuggingPriority:(UILayoutPriority)priority forAxis:(UILayoutConstraintAxis)axis;

實例代碼:

    [A setContentHuggingPriority:UILayoutPriorityRequired forAxis:UILayoutConstraintAxisHorizontal];
    [B setContentHuggingPriority:UILayoutPriorityDefaultLow forAxis:UILayoutConstraintAxisHorizontal];

由於B的抗拉伸值低，故需要拉伸時，優先拉伸B

 

設置抗壓縮性。 值越低，越容易被壓縮

- (void)setContentCompressionResistancePriority:(UILayoutPriority)priority forAxis:(UILayoutConstraintAxis)axis

實例代碼

    [A setContentCompressionResistancePriority:UILayoutPriorityRequired forAxis:UILayoutConstraintAxisHorizontal];
    [B setContentCompressionResistancePriority:UILayoutPriorityDefaultLow forAxis:UILayoutConstraintAxisHorizontal];

由於B的抗壓縮值低。故需要壓縮時，優先壓縮B