uikit——Auto Layout——UIView——constraint
来源:互联网 发布:思迅天店软件好不好 编辑:程序博客网 时间:2024/06/14 07:13
constraint
// Installing Constraints/* A constraint is typically installed on the closest common ancestor of the views involved in the constraint. It is required that a constraint be installed on _a_ common ancestor of every view involved. The numbers in a constraint are interpreted in the coordinate system of the view it is installed on. A view is considered to be an ancestor of itself. */@interface UIView (UIConstraintBasedLayoutInstallingConstraints)@property(nonatomic,readonly) NSArray<__kindof NSLayoutConstraint *> *constraints NS_AVAILABLE_IOS(6_0);- (void)addConstraint:(NSLayoutConstraint *)constraint NS_AVAILABLE_IOS(6_0); // This method will be deprecated in a future release and should be avoided. Instead, set NSLayoutConstraint's active property to YES.- (void)addConstraints:(NSArray<__kindof NSLayoutConstraint *> *)constraints NS_AVAILABLE_IOS(6_0); // This method will be deprecated in a future release and should be avoided. Instead use +[NSLayoutConstraint activateConstraints:].- (void)removeConstraint:(NSLayoutConstraint *)constraint NS_AVAILABLE_IOS(6_0); // This method will be deprecated in a future release and should be avoided. Instead set NSLayoutConstraint's active property to NO.- (void)removeConstraints:(NSArray<__kindof NSLayoutConstraint *> *)constraints NS_AVAILABLE_IOS(6_0); // This method will be deprecated in a future release and should be avoided. Instead use +[NSLayoutConstraint deactivateConstraints:].@end
解释:
- constraint通常关联着两个UI对象,假设两个UI对象closest common ancestor为ancestor,ancestor就是constraint拥有者
- 如果两个UI对象无common ancestor,add不成功,remove不属于receiver的constraint直接ignored,不会crash
- auto layout计算constraint时以拥有该constraint的view坐标系为参考坐标系
- iOS 8.0及以后,弃用这些方法了,通过设置active属性代替调用view的addConstraint和removeConstraint,设置active属性能自动把constraint add到correct view和自动把constraint从correct view remove
阅读全文
0 0
- uikit——Auto Layout——UIView——constraint
- uikit——Auto Layout——constraint
- uikit——Auto Layout——UIView——layout guide
- uikit——UIView——layout
- uikit——Auto Layout——UIView——anchor
- uikit——Auto Layout——UIView——margin
- uikit——Auto Layout——layout margin
- uikit——Auto Layout——intrinsic content size
- uikit——Auto Layout——Readable Content Guide
- uikit——Auto Layout——Semantic Content
- uikit——Auto Layout——NSLayoutConstraint
- uikit——Auto Layout——NSLayoutAnchor
- uikit——Auto Layout——UILayoutGuide
- uikit——UIView——layout定制
- uikit——Auto Layout——Top&Bottom Layout Guide
- UIView——layout
- uikit——UIView——drawing
- uikit——UIView——autoresizing
- 01好好学习读书笔记-- 什么是知识?
- react-native-debugger调试工具
- POJ
- HDU1060 Leftmost Digit
- Linux驱动编程——设备树
- uikit——Auto Layout——UIView——constraint
- Unity3D学习记录——NGUI Sprit2
- How to reload/restart php7.0-fpm / php5.0-fpm service
- 类模板-
- 单链表的基础面试题
- python 37 pandas操作csv文件小结,csv文件合并
- CSU-ACM2017暑假集训2-二分搜索 F
- offer面试题----打印1到最大的n位数
- 【网络开发】详谈socket请求Web服务器过程