How Do I Add UIViewController to UIScrollView in Swift - ios

Question

I want to have a UIScrollView of UIViewControllers. I tested the ScrollView and it works fine, except when I try to add the ViewControllers. The project builds fine, but I get a "fatal error: unexpectedly found nil while unwrapping an Optional value" error that points at the ViewController, particularly the line:
self.imageView.image = UIImage(named: self.image!)
However, when I inspect the object, I can see variables image and text have values in the ViewController. I'm using Xcode 6.3 Beta and building to iOS8.1 target.
Here's the code:
import UIKit
class ViewController: UIViewController {
//#IBOutlet weak var contentScrollView: UIScrollView!
#IBOutlet var contentScrollView: UIScrollView!
//test to make sure ScrollView functions
//let colors = [UIColor.redColor(),UIColor.blueColor(), UIColor.greenColor(), UIColor.whiteColor(), UIColor.blackColor(), UIColor.yellowColor()]
var frame = CGRectMake(0, 0, 0, 0)
var dataArray = [PostItem]()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
var da = PostItem(text: "test 1", pic: "beans.jpg")
self.dataArray.append(da!)
da = PostItem(text: "test 2", pic: "coffee.jpg")
self.dataArray.append(da!)
da = PostItem(text: "test 3", pic: "coffeeCup.jpg")
self.dataArray.append(da!)
for index in 0..<self.dataArray.count{
self.frame.origin.y = self.contentScrollView.frame.size.height * CGFloat(index)
self.frame.size = self.contentScrollView.frame.size
self.contentScrollView.pagingEnabled = false
let tempPost = self.dataArray[index]
var vc = PostViewController()
vc.text = tempPost.postText
vc.image = tempPost.postImage
self.contentScrollView.addSubview(vc.view)
}
self.contentScrollView.contentSize = CGSizeMake(self.view.frame.size.width, CGFloat(self.dataArray.count) * self.contentScrollView.frame.height)
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}}
And here is the code for the ViewController I want to add:
import UIKit
class PostViewController: UIViewController {
//let postItem
#IBOutlet weak var imageView: UIImageView!
#IBOutlet weak var postToFBButton: UIButton!
#IBOutlet weak var postToTwitterButton: UIButton!
#IBOutlet weak var postText: UILabel!
var image:String?
var text:String?
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
self.imageView.image = UIImage(named: self.image!)
self.postText.text = text!
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}}

Answer 1

The fix is to create the PostViewController through instantiateViewControllerWithIdentifier from storyboard, this way, it will have an imageView loaded from storyboard when its view is added to the scrollview.