iOS Swift Custom Cell NavigationController

Question

I have CollectionView in TableView. everything ok but. when I want to navigate my cell to another viewController I got error

func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath){

    let storyboard = UIStoryboard(name: "Main", bundle: NSBundle.mainBundle())

    let bookView: BookSingleController = storyboard.instantiateViewControllerWithIdentifier("BookSingle") as! BookSingleController

    self.navigationController?.pushViewController(bookView, animated: true)


    bookView.bookID = "\(self.books[indexPath.row].id)"

    print(self.books[indexPath.row].id)
}

Xcode show me error on self.navigationController?.pushViewController(bookView, animated: true) line. this is error description:

Value of 'RelatedBookTableViewCell' has no member 'navigationController'

RelatedBookTableViewCell is my custom cell class:

class RelatedBookTableViewCell: UITableViewCell, UICollectionViewDataSource, UICollectionViewDelegate, UICollectionViewDelegateFlowLayout

Where is my problem?

thanks.

Answer 1

You will either need to:

1. Use a delegate pattern like some have suggested.

Where you pass the call from the collectionView delegate method didSelectItemAtIndexPath to your own custom delegate/protocol on the cell that the UITableViewController which displays the cell is a delegate to. This can be set in the cellForRowAtIndexPath.

swift

Custom Protocol

protocol DisplayBookDelegate { func displayBook(bookId: String) }

In the tableViewController

class tableViewController: UITableViewController, DisplayBookDelegate {

    ...

    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        let cell = UITableViewCell()
        cell.delegate = self
        return UITableViewCell()
    }

    func displayBook(let bookId) {
        self.navigationController?.pushViewController(bookView, animated: true)
    }
}

In the cell

var delegate: DisplayBookDelegate?

func collectionView(collectionView: UICollectionView, didSelectItemAtIndexPath indexPath: NSIndexPath) {
    self.delegate.displayBook("1")
}

1. Use notifications and pass the bookId in a dictionary on the notification object

objc : [[NSNotificationCenter defaultCenter] postNotificationName:"kDisplayBookView" object:@{"bookId":"1"}];

swift NSNotificationCenter.defaultCenter().postNotificationName("kDisplayBookView", object: ["bookId":"1"])

Answer 2

Using below code you can get the Top viewcontroller and using that view controller you can perform your push operation

  let objViewController = UIApplication.topViewController()!

Use this extension

extension UIApplication {
    class func topViewController(base: UIViewController? = UIApplication.sharedApplication().keyWindow?.rootViewController) -> UIViewController? {
        if let nav = base as? UINavigationController {
            return topViewController(nav.visibleViewController)
        }
        if let tab = base as? UITabBarController {
            if let selected = tab.selectedViewController {
                return topViewController(selected)
            }
        }
        if let presented = base?.presentedViewController {
            return topViewController(presented)
        }
        return base
    }
}

Answer 3

尝试从应用程序的根控制器中推送VC。

UIApplication.sharedApplication().keyWindow?.rootViewController