从 splitviewcontroller 中的 masterVewController 访问 ROOT detailViewController

Question

Here is the layout of my app

I am trying to access a variable of startViewController from within TableViewController.

When I print the viewControllers of splitViewController ( print(self.splitViewController?.viewControllers) ) from within tableViewController this is what I get

Optional([<UINavigationController: 0x12200f600>, <temp.CollectionViewController: 0x121e16860>])

That second viewController( temp.CollectionViewController ) should be of type startViewController.

The startViewController in my program presents the collectionViewController using a segue with kind show. The collectionViewController has already been segued to when I call print(self.splitViewController?.viewControllers) .

Answer 1

try to cast it as below :

splitViewController?.viewControllers.forEach({ (vc) in
  if let startController = vc as? startViewController {
    --- Your code ---
    return
  }            
})

Answer 2

I ended up needing to put StartViewController inside a UINavigationController. I was then able to access the first viewController with

var detailStart = (splitViewController?.viewControllers[1] as? UINavigationController)?.viewControllers.first as? StartViewController

I then hid the unwanted navigation bar with

navigationController?.setNavigationBarHidden(true, animated: false)

Which was placed inside viewDidAppear

---

This ended up being an ok solution for me, because I needed to put CollectionViewController inside a UINavigationController anyway, but it seems kind of hacky and maybe not the best practice