First iOS app in Swift - Question marks in UIPickerView - ios

Question

I'm working on my first Swift ios application.
Can't get data from pickerData into my picker, but I only get question marks instead of real values. I guess it's something to do with delegate, but not sure what wrong.
import UIKit
import CoreData
class NewWorkoutController: UIViewController,UIPickerViewDelegate, UIPickerViewDataSource {
#IBOutlet weak var workoutDistance: UITextField!
let pickerData = ["11","12","13","14","15"]
// Data Sources
func numberOfComponentsInPickerView(distancePickerView: UIPickerView) -> Int {
return 1
}
func pickerView(distancePickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return pickerData.count
}
// Delegates
func pickerViewReturnRow(distancePickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String! {
return pickerData[row]
}
func pickerViewText(distancePickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
workoutDistance.text = pickerData[row]
}
func doneDistancePicker() {
workoutDistance.resignFirstResponder()
}
func cancelDistancePicker() {
workoutDistance.resignFirstResponder()
}
#IBAction func textFieldDistanceEditing2(sender: UITextField) {
// Create picker view
var distancePickerView: UIPickerView
distancePickerView = UIPickerView(frame: CGRectMake(0, 200, view.frame.width, 300))
distancePickerView.backgroundColor = .whiteColor()
distancePickerView.showsSelectionIndicator = true
distancePickerView.delegate = self
distancePickerView.dataSource = self
// Create toolbar
var toolBar = UIToolbar()
toolBar.barStyle = UIBarStyle.Default
toolBar.translucent = true
toolBar.tintColor = UIColor(red: 76/255, green: 217/255, blue: 100/255, alpha: 1)
toolBar.sizeToFit()
// Create buttons
var doneButton = UIBarButtonItem(title: "Done", style: UIBarButtonItemStyle.Plain, target: self, action: "doneDistancePicker")
var spaceButton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.FlexibleSpace, target: nil, action: nil)
var cancelButton = UIBarButtonItem(title: "Cancel", style: UIBarButtonItemStyle.Plain, target: self, action: "cancelDistancePicker")
// Assign buttons to toolbar
toolBar.setItems([cancelButton, spaceButton, doneButton], animated: false)
toolBar.userInteractionEnabled = true
// Add pickerview and toolbar to textfield
workoutDistance.inputView = distancePickerView
workoutDistance.inputAccessoryView = toolBar
sender.inputView = distancePickerView
}
override func viewDidLoad() {
super.viewDidLoad()
}
}

Answer 1

The signature for this function is wrong:
func pickerViewReturnRow(distancePickerView: UIPickerView,
titleForRow row: Int,
forComponent component: Int) -> String!
It should be
func pickerView(pickerView: UIPickerView,
titleForRow row: Int,
forComponent component: Int) -> String!
As a result that method (which provides titles for the rows in your picker) isn't getting called.

Answer 2

In all pickerView delegate method's signature, you replaced pickerView with your pickerView outlet that is distancePickerView which is not required. You should modify code inside delegate method's body because delegate methods are automatically called by swift compiler if we confirm your pickerView delegate and datasource to your ViewController class by writing code as:
pickerViewOutlet.delegate = self
pickerViewOutlet.dataSource = self
So just modify all pickerView delegate methods with its default signature then it will get called by compiler and data will display in it.