UIView.h解读

autoresizingMask

autoresizingMask

定义:

@property(nonatomic) UIViewAutoresizing autoresizingMask; // simple resize. default is UIViewAutoresizingNone

autoresizingMask是一个integer bit遮罩,决定了当父控件的bounds发生改变时,控件如何改变自己的尺寸 是一个枚举类型,有7种取值:

typedef NS_OPTIONS(NSUInteger, UIViewAutoresizing) { UIViewAutoresizingNone = 0, UIViewAutoresizingFlexibleLeftMargin = 1 << 0, UIViewAutoresizingFlexibleWidth = 1 << 1, UIViewAutoresizingFlexibleRightMargin = 1 << 2, UIViewAutoresizingFlexibleTopMargin = 1 << 3, UIViewAutoresizingFlexibleHeight = 1 << 4, UIViewAutoresizingFlexibleBottomMargin = 1 << 5 }; UIViewAutoresizingNone控件不改变尺寸.UIViewAutoresizingFlexibleLeftMargin 扩大或缩小左边间距UIViewAutoresizingFlexibleWidth扩大或缩小控件的宽度UIViewAutoresizingFlexibleRightMargin 扩大或缩小控件的右边边距.UIViewAutoresizingFlexibleTopMargin扩大或缩小控件的顶部边距.UIViewAutoresizingFlexibleHeight扩大或缩小控件的高度UIViewAutoresizingFlexibleBottomMargin扩大或缩小控件的底部边距.