iOS 关于UIViewAutoresizing autoresizingMask的记录

官方简介：

// simple resize. default is UIViewAutoresizingNone

An integer bit mask that determines how the receiver resizes itself when its superview’s bounds change.

ps:当父视图的bounds改变的时候，根据枚举的integer的类型自动调整位子

typedefNS_OPTIONS(NSUInteger, UIViewAutoresizing) {

UIViewAutoresizingNone =0, //!< 不进行自动调整

UIViewAutoresizingFlexibleLeftMargin =1 <<0,//!< 自动调整与superView的左边距离，保证右边距离不变

UIViewAutoresizingFlexibleWidth =1 <<1,//!< 自动调整自己的宽度，保证与superView左边和右边的距离不变

UIViewAutoresizingFlexibleRightMargin =1 <<2,//!< 与UIViewAutoresizingFlexibleLeftMargin相反

UIViewAutoresizingFlexibleTopMargin = 1 <<3,//!< 自动调整与superView顶部的距离，保证与bottom不变

UIViewAutoresizingFlexibleHeight =1 <<4,//!< 自动调整自己的高度，保证与superView顶部与底部不变

UIViewAutoresizingFlexibleBottomMargin =1 <<5 //!< 与UIViewAutoresizingFlexibleTopMargin相反

};

UIViewAutoresizingFlexibleWidth |UIViewAutoresizingFlexibleHeight 自动调整自己的宽度，保证现在宽高和之前的宽高比例不变。比如原来距离为20，40，调整后的距离应为75，，即75/20=150/40。

其它的组合类似。

简单概括就是出现哪个单词，就是哪个方向根据superView进行调整

举个栗子

1.UIViewAutoresizingNone








2.左下角不变，高度自由生长







注意用 | 隔开(左边不变就用UIViewAutoresizingFlexibleRightMargin)
view.autoresizingMask = UIViewAutoresizingFlexibleRightMargin
| UIViewAutoresizingFlexibleTopMargin | UIViewAutoresizingFlexibleHeight

还有个属性是 autoresizesSubviews

default is YES. if set, subviews are adjusted according to their autoresizingMask if self.bounds changes

默认是Yes,子视图根据autoresizingMask的值进行自动调整，如果设置成NO，那么autoresizingMask直接无效