如何比较Swift 3中的UIViewController？

Question

I am trying to compare to UIViewController in Swift 3 but there is some error

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: Cannot convert value of type 'UIViewController' to expected argument type 'AnyClass' (aka 'AnyObject.Type')

and if try to use

if(vc is viewController)

It gives

/Users/varunnaharia/Documents/Projects/appname/appname/Public/UINavigationController+Extra.swift:18:22: Use of undeclared type 'viewController'

I am calling it through this

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

Answer 1

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

Answer 2

Swift 4 Hope it will work for you

   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

In swift, we use is instead of isKind(of:) .

is is used to check the type of the object .

So you can use,

if(vc is UIViewController)

But I think here you are trying to match the 2 references of UIViewController .

So, you need to use === instead of is . This operator is used to match 2 references of same type.

if(vc === viewController)

Answer 4

If you want to compare to a particular view controller you have to compare their refererences.

Try this...

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

Answer 5

Probably what you are looking for, is , a method that pops till a given controller, where the given controller is an object in current navigation stack.

So,

Here is the extension method that pops up all controllers above a given controller.

extension UINavigationController {
    func popTo(controllerToPop:UIViewController)  {
        let controllers = self.viewControllers
        for controller in controllers {
            if(controller == controllerToPop) {
                self.popTo(controllerToPop: controllerToPop)
            }
        }
    }
}

Answer 6

i just modify the answer of Mr. @BangOperator for move to particular View controller.

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)
    }
  }
}