准备好进行搜索后迅速关闭导航控制器

Question

I have the following schema: The controller in the upper right corner is SelectAlbumVC

The controller in the lower left corner is AddPhotoVC

In SelectAlbumVC i have this code:

override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    guard let destination = segue.destination as? AddPhotoPostVC
        else { fatalError("unexpected view controller for segue") }
    guard let cell = sender as? AlbumListCells else { fatalError("unexpected cell for segue") }

    switch SegueIdentifier(rawValue: segue.identifier!)! {
    case .showAllPhotos:
        destination.fetchResult = allPhotos
        destination.headerTitleBtnString = cell.allPhotoTitle.text!
    case .showCollection:
        // get the asset collection for the selected row
        let indexPath = tableView.indexPath(for: cell)!
        let collection: PHCollection
        switch Section(rawValue: indexPath.section)! {
        case .smartAlbums:
            collection = smartAlbums.object(at: indexPath.row)
        case .userCollections:
            collection = userCollections.object(at: indexPath.row)
        default: return // not reached; all photos section already handled by other segue
        }

        // configure the view controller with the asset collection
        guard let assetCollection = collection as? PHAssetCollection
            else { fatalError("expected asset collection") }
        destination.fetchResult = PHAsset.fetchAssets(in: assetCollection, options: nil)
        destination.assetCollection = assetCollection
        destination.headerTitleBtnString = cell.collectionTitle.text!
        destination.isComingFromSelectAlbum = true
    }
}

so basically when i click on a cell the segue will be executed and the data passed to AddPhotoVC. My issue is that when the segue is executed the navigation controller associated with SelectAlbumVC is not dismissed and so when clicking the dismissing button on the AddPhotoVC SelectAlbumVC is presented again (it's the last controller in the stack).

Is there a way to dismiss the navigation controller when the prepare for segue is called? I've tried to add the the bottom

self.navigationController?.popToRootViewController(animated: false)

but it does not work.

Any help will be really appreciated.

Thank you!

Answer 1

If I understand your code correctly, you're adding another segue back to AddPhotoVC. So if while your app was running and you clicked the "Debug View Hierarchy" (down by the debugger controls in Xcode) you'd see that you now have another AddPhotoVC on top of the original one.

Instead of performing a segue from SelectPhotoVC to AddPhotoVC you may want to consider performing an Unwind Segue instead. This way you could pass the values you want and all the previous VCs would be dismissed.

Answer 2

You are using (multiple) two UINavigationController . That means you are presenting the second screen instead of pushing it.

Now, you mentioned that popToRootViewController does not work, that's because again the two screens have two different UINavigationController . You should dismiss the second screen rather than popping it, because you presented it.

Know the different between pushing/show and presenting viewControllers.

Push/Show --- Pop.

Present --- Dismiss.

Instead of this self.navigationController?.popToRootViewController(animated: false)

Use this:

self.navigationController?.dismiss(animated: true, completion: {
    // completion, do something or make it nil.
})