UIViewController中view在navBar和tabBar影响下布局区域问题

转自:https://www.cnblogs.com/bridge-wuxl/p/10790888.html

影响 View 布局区域的有以下三个属性: self.edgesForExtendedLayout (影响View布局区域的主要属性)
self.navigationController.navigationBar.translucent (navigationBar 是否半透明) self.tabBarController.tabBar.translucent (tabBar 是否半透明)

case 1: edgesForExtendedLayout = UIRectEdgeAll
条件: navigationBar.translucent = YES && tabBar.translucent = YES
结果: View Top == navigationBar Top，View Bottom == tabBar Bottom

条件: navigationBar.translucent = NO && tabBar.translucent = YES
结果: View Top == navigationBar Bottom，View Bottom == tabBar Bottom

条件: navigationBar.translucent = YES && tabBar.translucent = NO
结果: View Top == navigationBar Top，View Bottom == tabBar Top

条件: navigationBar.translucent = NO && tabBar.translucent = NO
结果: View Top == navigationBar Bottom，View Bottom == tabBar Top

case 2: edgesForExtendedLayout = UIRectEdgeTop
条件: navigationBar.translucent = YES && tabBar.translucent = YES
结果: View Top == navigationBar Top，View Bottom == tabBar Top

条件: navigationBar.translucent = NO && tabBar.translucent = YES
结果: View Top == navigationBar Bottom，View Bottom == tabBar Top

条件: navigationBar.translucent = YES && tabBar.translucent = NO
结果: View Top == navigationBar Top，View Bottom == tabBar Top

条件: navigationBar.translucent = NO && tabBar.translucent = NO
结果: View Top == navigationBar Bottom，View Bottom == tabBar Top

case 3: edgesForExtendedLayout = UIRectEdgeBottom
条件: navigationBar.translucent = YES && tabBar.translucent = YES
结果: View Top == navigationBar Bottom，View Bottom == tabBar Bottom

条件: navigationBar.translucent = NO && tabBar.translucent = YES
结果: View Top == navigationBar Bottom，View Bottom == tabBar Bottom

条件: navigationBar.translucent = YES && tabBar.translucent = NO
结果: View Top == navigationBar Bottom，View Bottom == tabBar Top

条件: navigationBar.translucent = NO && tabBar.translucent = NO
结果: View Top == navigationBar Bottom，View Bottom == tabBar Top

case 4: edgesForExtendedLayout = UIRectEdgeNone
条件: navigationBar.translucent = YES && tabBar.translucent = YES
结果: View Top == navigationBar Bottom，View Bottom == tabBar Top

条件: navigationBar.translucent = NO && tabBar.translucent = YES
结果: View Top == navigationBar Bottom，View Bottom == tabBar Top

条件: navigationBar.translucent = YES && tabBar.translucent = NO
结果: View Top == navigationBar Bottom，View Bottom == tabBar Top

条件: navigationBar.translucent = NO && tabBar.translucent = NO
结果: View Top == navigationBar Bottom，View Bottom == tabBar Top

iOS 7.0以后
self.navigationController.navigationBar.translucent 和 self.tabBarController.tabBar.translucent 默认值都为 YES.

iOS 6.0以下系统
navigationBar 和 tabBar 默认都是不透明的。edgesForExtendedLayout 的枚举项:
UIRectEdgeNone = 0, navBar 底部与 tabBar 上部之间
UIRectEdgeTop = 1 << 0, navBar 上部与 tabBar 上部之间
UIRectEdgeLeft = 1 << 1,
UIRectEdgeBottom = 1 << 2, navBar 底部与 tabBar 底部之间
UIRectEdgeRight = 1 << 3,
UIRectEdgeAll = UIRectEdgeTop | UIRectEdgeLeft | UIRectEdgeBottom | UIRectEdgeRight下面图中展示了 UIView 的四种情况下的布局区域，

绿色为目标 UIView:
View Top == navigationBar Bottom，View Bottom == tabBar Top

View Top == navigationBar Top，View Bottom == tabBar Bottom

View Top == navigationBar Bottom，View Bottom == tabBar Bottom

View Top == navigationBar Top，View Bottom == tabBar Top

注：我在iOS17.2模拟器上测验过！