如何比较Swift 3中的UIViewController？

Question

我想在Swift 3中与UIViewController进行比较,但是有一些错误

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:无法将'UIViewController'类型的值转换为预期的参数类型'AnyClass'(又名'AnyObject.Type')

如果尝试使用

if(vc is viewController)

它给

/Users/varunnaharia/Documents/Projects/appname/appname/Public/UINavigationController+Extra.swift:18:22:使用未声明的类型'viewController'

我通过这个称呼它

self.navigationController?.popOrPopToViewController(viewController: MyUIViewController(), animated: false)

Answer 1

for viewsController in arrViewControllers
{
    if(viewsController.isKind(of: YourControllerClassName.self)){
    }
}

Answer 2

Swift 4 希望它对你有用

   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))
      }
    }
  }

}

Answer 3

在 swift 中，我们使用 is代替isKind(of:).

is用于检查type of the object.

所以你可以使用，

if(vc is UIViewController)

但我认为你在这里试图 match the 2 references of UIViewController。

因此，您需要使用===而不是is. 此运算符用于匹配 2 个相同类型的引用。

if(vc === viewController)

Answer 4

如果您想与特定视图控制器进行比较，您必须比较它们的引用。

尝试这个...

if(vc === viewController) )
{
    return (self.navigationController?.popToViewController(vc, animated: animated)?.last)!
}