How to navigate from UITableViewCell to UICollectionViewController programmatically in Swift 4 - ios

Question

Here is what I want to achieve: When I tap a UITabViewCell (Picture 1), it will navigate to an UICollectionViewController (Picture 2). Just like the following two pictures showing:
I could navigate to an UIViewController when tap a UITableViewCell, but it doesn't work when I try to navigate to UICollectionView. Here are my codes:
import UIKit
class RealUserProfileController: UIViewController, UITableViewDelegate, UITableViewDataSource {
private let me = ["Vincent-St"]
private let followers = ["58 Followers"]
private let myPhotos = ["New Followers"]
private let others = ["My likes", "Notifications", "Clear Caches", "Drafts"]
private let settings = ["Settings"]
private let share = ["Share with friends"]
private let images = ["Hearts.png", "Footprint.png", "Notifications.png", "Trash-Empty.png"]
private let sections = ["me", "myPhotos", "others", "settings", "share"]
override func viewDidLoad() {
super.viewDidLoad()
self.navigationController?.navigationBar.titleTextAttributes = [NSAttributedStringKey.font: UIFont(name: "Arial", size: 18)!, NSAttributedStringKey.foregroundColor: UIColor.black]
navigationItem.title = "Profile"
let displayWidth: CGFloat = self.view.frame.width
let displayHeight: CGFloat = self.view.frame.height
let myTableView: UITableView = UITableView(frame: CGRect(x: 0, y: 0, width: displayWidth, height: displayHeight), style: .grouped)
myTableView.register(UITableViewCell.self, forCellReuseIdentifier: "MyCell")
myTableView.dataSource = self
myTableView.delegate = self
self.view.addSubview(myTableView)
view.backgroundColor = UIColor(white: 1, alpha: 0.95)
myTableView.translatesAutoresizingMaskIntoConstraints = false
myTableView.topAnchor.constraint(equalTo: view.topAnchor, constant: -20).isActive = true
myTableView.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
myTableView.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
myTableView.bottomAnchor.constraint(equalTo: view.bottomAnchor).isActive = true
}
func numberOfSections(in tableView: UITableView) -> Int {
return sections.count
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
if indexPath.section == 0 {
return 72
}
return tableView.rowHeight
}
func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
if indexPath.section == 0 {
let controller = UserProfileController()
self.navigationController?.pushViewController(controller, animated: true)
print("Value: \(me[indexPath.row])")
} else if indexPath.section == 1 {
print("Value: \(myPhotos[indexPath.row])")
} else if indexPath.section == 2 {
print("Value: \(others[indexPath.row])")
} else if indexPath.section == 3 {
let controller = ResultController()
navigationController?.pushViewController(controller, animated: true)
print("Value: \(settings[indexPath.row])")
} else if indexPath.section == 4 {
print("Value: \(share[indexPath.row])")
let shareText = "Share our app"
let shareImage = UIImage(named: "bell_unselected.png")
let activityViewController : UIActivityViewController = UIActivityViewController(activityItems: [shareText, shareImage as Any], applicationActivities: nil)
self.present(activityViewController, animated: true, completion: nil)
}
}
// return the number of cells each section.
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
if section == 0 {
return me.count
} else if section == 1 {
return myPhotos.count
} else if section == 2 {
return others.count
} else if section == 3 {
return settings.count
} else if section == 4 {
return share.count
} else {
return 0
}
}
// return cells
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell: UITableViewCell = UITableViewCell(style: UITableViewCellStyle.subtitle, reuseIdentifier: "MyCell")
if indexPath.section == 0 {
cell.textLabel?.text = "\(me[indexPath.row])"
cell.detailTextLabel?.text = "\(followers[indexPath.row])"
cell.imageView?.image = #imageLiteral(resourceName: "profile_image")
} else if indexPath.section == 1 {
cell.textLabel?.text = "\(myPhotos[indexPath.row])"
cell.imageView?.image = #imageLiteral(resourceName: "icon_friends")
} else if indexPath.section == 2 {
cell.textLabel?.text = "\(others[indexPath.row])"
cell.imageView?.image = UIImage.init(named: images[indexPath.row])
} else if indexPath.section == 3 {
cell.textLabel?.text = "\(settings[indexPath.row])"
cell.imageView?.image = #imageLiteral(resourceName: "Icon_Settings")
} else if indexPath.section == 4 {
cell.textLabel?.text = "\(share[indexPath.row])"
cell.imageView?.image = #imageLiteral(resourceName: "Share")
}
cell.accessoryType = .disclosureIndicator
return cell
}
}
The two lines of codes will crash the app:
let controller = UserProfileController()
self.navigationController?.pushViewController(controller, animated: true)
Here is the error message:
Cannot convert value of type 'UserProfileController.Type' to expected argument type 'UIViewController'
Here are the codes of the destination UICollectionViewController:
class UserProfileController: UICollectionViewController, UICollectionViewDelegateFlowLayout {
}
After some research, I didn't find any useful information. Is there any way to make it happen? Or is there any way to implement the Picture 2 in another way, maybe: UIViewController, instead of UICollectionView?
Any suggestion would be appreciated.

Answer 1

I don't think the problem is with navigation, any subclass of UIViewController should be navigable.
I believe you need to initialize UICollectionViewController using init(collectionViewLayout: UICollectionViewLayout), collectionView has to have the layout set, otherwise the collectionView will crash if it gets presented.
Therefore instead of:
let controller = UserProfileController()
try using:
let controller = UserProfileController(collectionViewLayout: UICollectionViewFlowLayout())
Here I am assuming that the following code is your full implementation of UserProfileController, thus you directly inherit initializers from UICollectionViewController:
class UserProfileController: UICollectionViewController, UICollectionViewDelegateFlowLayout {
}