CSS修复容器和溢出元素(CSS Fix container and overflow elements)

 您需要创建自己的条形按钮项并将其分配给先前的视图控制器navigationItem backBarButtonItem属性，例如： 
 
UIBarButtonItem *temporaryBarButtonItem = [[UIBarButtonItem alloc] init];
temporaryBarButtonItem.title = NSLocalizedString(@"MAIN", @"Back bar button item to go back to the main view controller");
self.navigationItem.backBarButtonItem = temporaryBarButtonItem;
 
 检查UINavigationItem类引用以确保将上面的代码放在正确的视图控制器中，尤其是这部分： 
 
 
 
 当此导航项位于堆栈顶部项目的正下方时 ，导航控制器将从此导航项目中导出导航栏的后退按钮。 
 

You need to create your own bar button item and assign it to the previous view controller navigationItem backBarButtonItem property, for example:
 
UIBarButtonItem *temporaryBarButtonItem = [[UIBarButtonItem alloc] init];
temporaryBarButtonItem.title = NSLocalizedString(@"MAIN", @"Back bar button item to go back to the main view controller");
self.navigationItem.backBarButtonItem = temporaryBarButtonItem;
 
Check the UINavigationItem class reference to make sure you put the codes above in the correct view controller, especially this part:
 
 
 
When this navigation item is immediately below the top item in the stack, the navigation controller derives the back button for the navigation bar from this navigation item.