How to use NSUserDefault with PickerView in Swift? - swift

Question

I made some Labels that change using PickerView. But when I change the Label and if I run my app again, it doesn't save to selected one. So I have to use NSUserDefault but I don't know how to use it in right way.
This is my code:
var selectedFood = 0
class ViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {
#IBOutlet var foodLabel: UILabel!
#IBOutlet var labelTwo: UILabel!
#IBOutlet var labelThree: UILabel!
#IBOutlet weak var foodPicker: UIPickerView!
var food = ["Bread", "Pizza", "Pasta", "Hot Dog", "Burger"]
#IBAction func submitLanguageButton(sender: AnyObject) {
if (selectedFood == 0) {
foodLabel.text = "Bread"
labelTwo.text = "Bread is a staple food prepared from a dough of flour and water..."
labelThree.text = "Bread is one of the oldest prepared foods..." // I used random information just as sample
}
else if (selectedFood == 1) {
foodLabel.text = "Pizza"
labelTwo.text = "Here will be more informations about Pizza"
labelThree.text = "A fact about Pizza" // I used random information just as sample
}
else if (selectedFood == 2) {
foodLabel.text = "Pasta"
labelTwo.text = "Here will be more informations about Pasta"
labelThree.text = "A fact about Pasta" // I used random information just as sample
}
else if (selectedFood == 3) {
foodLabel.text = "Hot Dog"
labelTwo.text = "Here will be more informations about Hot Dog"
labelThree.text = "A fact about Hot Dog" // I used random information just as sample
}
else if (selectedFood == 4) {
foodLabel.text = "Burger"
labelTwo.text = "Here will be more informations about Burger"
labelThree.text = "A fact about Burger" // I used random information just as sample
}
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
foodPicker.delegate = self
foodPicker.dataSource = self
if (selectedFood == 0) {
foodLabel.text = "Bread"
labelTwo.text = "Bread is a staple food prepared from a dough of flour and water..."
labelThree.text = "Bread is one of the oldest prepared foods..." // I used random information just as sample
}
else if (selectedFood == 1) {
foodLabel.text = "Pizza"
labelTwo.text = "Here will be more informations about Pizza"
labelThree.text = "A fact about Pizza" // I used random information just as sample
}
else if (selectedFood == 2) {
foodLabel.text = "Pasta"
labelTwo.text = "Here will be more informations about Pasta"
labelThree.text = "A fact about Pasta" // I used random information just as sample
}
else if (selectedFood == 3) {
foodLabel.text = "Hot Dog"
labelTwo.text = "Here will be more informations about Hot Dog"
labelThree.text = "A fact about Hot Dog" // I used random information just as sample
}
else if (selectedFood == 4) {
foodLabel.text = "Burger"
labelTwo.text = "Here will be more informations about Burger"
labelThree.text = "A fact about Burger" // I used random information just as sample
}
}
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
return food[row]
}
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return food.count
}
public func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
selectedFood = row
}
}
So when I choose Pizza, whenever I run my app I want to be it Pizza, if I select another one for example Pasta, I want to be that one Pasta.
Can you please help me ?

Answer 1

WBMDDrugManagerErrorCodeSave the selection like so:
func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
NSUserDefaults.standardUserDefaults().setInteger(row, forKey: "choosenFood")
NSUserDefaults.standardUserDefaults().synchronize()
self.setLabelsForChoice(row)
}
Retrieve the chosen selection like so:
override func viewWillAppear() {
super.viewWillAppear()
if let previousSelection:Int = NSUserDefaults.standardUserDefaults().integerForKey("choosenFood") as? Int{
self.setLabelsForChoice(previousSelection)
}
}
Create a label update method similar to this:
func setLabelsForChoice(_choice:Int){
switch _choice{
case 0:
foodLabel.text = "Bread"
labelTwo.text = "Bread is a staple food prepared from a dough of flour and water..."
labelThree.text = "Bread is one of the oldest prepared foods..."
break
case 1:
foodLabel.text = "Pizza"
labelTwo.text = "Here will be more informations about Pizza"
labelThree.text = "A fact about Pizza"
break
default:
break
}
}