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[英]How to compare switch case with UIViewController as input in swift 2
[英]How to compare UIViewController in Swift 3?
我想在Swift 3中與UIViewController進行比較,但是有一些錯誤
extension UINavigationController
{
func myPopToViewController(viewController:UIViewController, animated:Bool) -> UIViewController? {
var arrViewControllers:[UIViewController] = []
arrViewControllers = self.viewControllers
for vc:UIViewController in arrViewControllers {
if(vc.isKind(of: viewController) ) // This Line gives me error
{
return (self.navigationController?.popToViewController(vc, animated: animated)?.last)!
}
}
return nil
}
}
/Users/varunnaharia/Documents/Projects/appname/appname/Public/UINavigationController+Extra.swift:18:30:無法將'UIViewController'類型的值轉換為預期的參數類型'AnyClass'(又名'AnyObject.Type')
如果嘗試使用
if(vc is viewController)
它給
/Users/varunnaharia/Documents/Projects/appname/appname/Public/UINavigationController+Extra.swift:18:22:使用未聲明的類型'viewController'
我通過這個稱呼它
self.navigationController?.popOrPopToViewController(viewController: MyUIViewController(), animated: false)
for viewsController in arrViewControllers
{
if(viewsController.isKind(of: YourControllerClassName.self)){
}
}
Swift 4希望它對你有用
extension UINavigationController {
func myPopToViewController(viewController:UIViewController, animated:Bool) {
var arrViewControllers:[UIViewController] = []
arrViewControllers = self.viewControllers
for vc:UIViewController in arrViewControllers {
if(vc.isKind(of: viewController.classForCoder)){
(self.popToViewController(vc, animated: animated))
}
}
}
}
在swift中,我們使用is
而不是isKind(of:)
。
is
用於檢查type of the object
的type of the object
。
所以你可以使用,
if(vc is UIViewController)
但我想在這里你試圖match the 2 references of UIViewController
。
所以,你需要使用===
而不是is
。 此運算符用於匹配2個相同類型的引用。
if(vc === viewController)
如果要與特定視圖控制器進行比較,則必須比較它們的參考。
嘗試這個...
if(vc === viewController) )
{
return (self.navigationController?.popToViewController(vc, animated: animated)?.last)!
}
可能你正在尋找的是一種方法,直到給定的控制器,其中給定的控制器是當前導航堆棧中的對象。
所以,
這是一個擴展方法,彈出給定控制器上方的所有控制器。
extension UINavigationController {
func popTo(controllerToPop:UIViewController) {
let controllers = self.viewControllers
for controller in controllers {
if(controller == controllerToPop) {
self.popTo(controllerToPop: controllerToPop)
}
}
}
}
我只是修改了@BangOperator先生的答案,轉移到特定的View控制器。
extension UINavigationController {
func popTo(controllerToPop:UIViewController) {
//1. get all View Controllers from Navigation Controller
let controllersArray = self.viewControllers
//2. check whether that view controller is exist in the Navigation Controller
let objContain: Bool = controllersArray.contains(where: { $0 == controllerToPop })
//3. if true then move to that particular controller
if objContain {
self.popToViewController(controllerToPop, animated: true)
}
}
}
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