How to connect UIPickerView + Button + call dictionary to display in label - swift

Question

I have a label, a picker (years), and a button. I want to be able to select the year on the picker, hit the button, and then display data associated with the year (a dictionary). Here's my code so far
class ViewController: UIViewController {
#IBOutlet weak var label: UILabel!
#IBOutlet weak var picker: UIPickerView!
func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent
component: Int) -> Int {
return years.count
}
func pickerView(pickerView: UIPickerView, titleForRow row: Int,
forComponent component: Int) -> String! {
return years[row]
}
/* func pickerView(pickerView: UIPickerView!, didSelectRow row: Int,
inComponent component: Int) {
label.text = "\(years[row])"
}
*/
#IBAction func button(sender: UIButton) {
label.text =
}
here is my Model:
let years = ["2015", "2014", "2013", "2012"]
let winners = [
2015: "Patriots",
2014: "Seahawks",
2013: "Ravens",
2012: "Giants"
]

Answer 1

You need to do a few things to make this work. First, make your viewController conform to the UIPickerViewDataSource and UIPickerViewDelegate and set your picker's data source and delegate in viewDidLoad. Then you'll want to use the delegate method pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) to respond to changes to the pickerView. Store the selection in an instance variable and you should be good to go:
class ViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {
#IBOutlet weak var label: UILabel!
#IBOutlet weak var picker: UIPickerView!
let years = [2015, 2014, 2013, 2012]
let winners = [
2015: "Patriots",
2014: "Seahawks",
2013: "Ravens",
2012: "Giants"
]
var selectedYear: Int?
override func viewDidLoad() {
super.viewDidLoad()
picker.delegate = self
picker.dataSource = self
}
func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return years.count
}
func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
selectedYear = years[row]
}
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String! {
return "\(years[row])"
}
#IBAction func button(sender: UIButton) {
if let year = selectedYear {
if let winner = winners[year] {
label.text = winner
}
}
}
}