Swift --棒棒糖4--判断当前的控制器是怎么来的

    extension UIViewController {
    
    
        var isModal: Bool {
    
    
            let presentingIsModal = presentingViewController != nil
            let presentingIsNavigation = navigationController?.presentingViewController?.presentedViewController == navigationController
            let presentingIsTabBar = tabBarController?.presentingViewController is UITabBarController
            
            return presentingIsModal || presentingIsNavigation || presentingIsTabBar
        }
    }
    你可以像这样写一个UIViewController的分类，也可以：
            var isModal: Bool {
    
    
            let presentingIsModal = presentingViewController != nil
            let presentingIsNavigation = navigationController?.presentingViewController?.presentedViewController == navigationController
            let presentingIsTabBar = tabBarController?.presentingViewController is UITabBarController
            
            return presentingIsModal || presentingIsNavigation || presentingIsTabBar
        }
这样单写一个属性，到你要查看怎么来的控制器里，即可，非常好使！