Error While Loading Table After Swift 2 Upgrade - IOS - ios

Question

When I try to make a dynamic table view with the code below I get the error "unexpectedly found nil while unwrapping an Optional value". Any ideas? I checked the array with print() but they are not empty.
import UIKit
class mainVC: UIViewController, UITableViewDataSource, UITableViewDelegate {
#IBOutlet weak var resultsTable: UITableView!
var resultsNameArray = [String]()
var resultsAlloCommentArray = [String]()
override func viewDidLoad() {
super.viewDidLoad()
let theWidth = view.frame.size.width
let theHeight = view.frame.size.height
resultsTable.frame = CGRectMake(0, 0, theWidth, theHeight)
refreshResults()
}
func refreshResults() {
resultsNameArray.removeAll(keepCapacity: false)
resultsAlloCommentArray.removeAll(keepCapacity: false)
let query = PFQuery(className: "posts")
query.addDescendingOrder("createdAt")
query.includeKey("relUserPointer")
query.limit = 10
query.findObjectsInBackgroundWithBlock {
(objects:[PFObject]?, error:NSError?) -> Void in
if error == nil {
for object in objects! {
self.resultsNameArray.append(object.objectForKey("profileName") as! String)
self.resultsAlloCommentArray.append(object.objectForKey("relUserPointer")!.objectForKey("settingAllowComment") as! String)
}
}
print(self.resultsNameArray)
print(self.resultsAlloCommentArray)
self.resultsTable.reloadData()
}
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
override func viewWillAppear(animated: Bool) {
}
override func viewDidAppear(animated: Bool) {
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return 10
}
func tableView(tableView: UITableView, heightForRowAtIndexPath indexPath: NSIndexPath) -> CGFloat {
return 127
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
//here I get the error in the dequeueReusableCellWithIdentifier
let cell:mainCell = tableView.dequeueReusableCellWithIdentifier("Cell") as! mainCell
cell.profileLbl.setTitle(self.resultsNameArray[indexPath.row], forState: UIControlState.Normal)
return cell
}
}

Answer 1

Your view controller class declaration says this:
class mainVC: UIViewController, UITableViewDataSource, UITableViewDelegate {
So this is a UIViewController - not a UITableViewController.
Therefore, the cells cannot come out of the storyboard as prototype cells. Only a UITableViewController can do that.
So, either you must make this a UITableViewController (here and in the storyboard), or else you must get the cells from somewhere else by calling registerClass:... or registerNib:... on your table view beforehand.
Finally, and most important, you are calling the wrong method here:
tableView.dequeueReusableCellWithIdentifier("Cell")
No. You should call
tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath:indexPath)
That way, you will always get a cell. The way you are doing it, you can get nil (as you've discovered). You must then make the cell yourself, which you are failing to do; you are not even testing for nil, which is why you are crashing.
One last thing. This has nothing to do with iOS 9 or Swift 2.0. If you think it does, you're just fooling yourself. Your code would have failed in exactly the same way in iOS 8 and Swift 1.2.

Answer 2

Try changing this line :
let cell:mainCell = tableView.dequeueReusableCellWithIdentifier("Cell") as! mainCell
to
let cell:mainCell = self.tableView.dequeueReusableCellWithIdentifier("Cell") as! mainCell