Reputation: 119
Looking for a solution to populate a picker view depending on the selection of another picker view within the same view controller. The first selects a category. The second the items of that category.
Here's what I (Swift beginner) came up with:
import UIKit
class ViewController: UIViewController, UIPickerViewDataSource, UIPickerViewDelegate {
var countryClasses = ["US", "EU", "JP"]
var usItems = ["usitem1", "usitem2", "usitem3", "usitem4", "usitem5"]
var euItems = ["euitem1", "euitem2", "euitem3", "euitem4", "euitem5"]
var jpItems = ["jpitem1", "jpitem2", "jpitem3", "jpitem4", "jpitem5"]
@IBOutlet weak var countryPicker: UIPickerView!
@IBOutlet weak var itemPicker: UIPickerView!
override func viewDidLoad() {
super.viewDidLoad()
self.countryPicker.dataSource = self;
self.countryPicker.delegate = self;
self.itemPicker.dataSource = self;
self.itemPicker.delegate = self;
}
func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return countryClasses.count
}
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String! {
return countryClasses[row]
}
}
Upvotes: 2
Views: 3982
Reputation: 17
Thanks @Wez!
In Swift 2.2, small but important correction return the function as String makes it works great.
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String! {
if pickerView == countryPicker {
return countryClasses[row]
} else if pickerView == itemPicker {
return selectedItemsArray[row]
}
return selectedItemsArray[row] as? String
}
Upvotes: 0
Reputation: 10712
As both the Pickers are using the same delegate you are going to need a way to identify them when your delegate methods run, also your current Array structure means you are going to need a way to select each item array as and when the country is selected.
Create a store for the selected item array.
var selectedItemsArray = []
Add some checks to your delegate methods.
func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
if pickerView == countryPicker {
return countryClasses.count
} else if pickerView == itemPicker {
return selectedItemsArray.count
}
return 0
}
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String! {
if pickerView == countryPicker {
return countryClasses[row]
} else if pickerView == itemPicker {
return selectedItemsArray[row]
}
return 0
}
Then you need to implement did Select row to setup the item store and reload the data.
func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
if pickerView == countryPicker {
switch row {
case 0:
selectedItemsArray = usItems
case 1:
selectedItemsArray = euItems
case 2:
selectedItemsArray = jpItems
default:
selectedItemsArray = []
}
// IMPORTANT reload the data on the item picker
itemPicker.reloadAllComponents()
} else if pickerView == itemPicker {
// Get the current item
var item = selectedItemsArray[row]
// Assign value to a label based on which array we are using
if selectedItemsArray == usItems {
usLabel.text = item
} else if selectedItemsArray == euItems {
euLabel.text = item
} else if selectedItemsArray == jpItems {
jpLabel.text = item
}
}
}
I haven't tested this code, but the logic should be correct.
Upvotes: 1
Reputation: 7840
Associate each picker view with a TAG (so that they can be identified) then in picker delegate identify these pickers on basis of these identiers and show other one
Upvotes: 0