Showing UIPickerView with selected row

Question

I am trying to figure out how to show the selected row when i open UIPickerView after it has been selected last time.

When I open my PickerView again, I want my UIPickerView to set selected row which I choose at last time.

Is there any way in Swift?

score 21 · Answer 1 · edited Mar 08 '17 at 12:40

You can save the last selected row in NSUserDefaults, retrieve the value in viewDidLoad of your view controller and your picker's selected row to the index of the selected value from an array of values.

class Pick: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {

var picker = UIPickerView()
var selected: String {
    return NSUserDefaults.standardUserDefaults().stringForKey("selected") ?? ""
}
var data = ["One", "Two", "Three"]

override func viewDidLoad() {
    super.viewDidLoad()
    picker.delegate = self
    picker.dataSource = self
    if let row = data.indexOf(selected) {
        picker.selectRow(row, inComponent: 0, animated: false)
    }
}

func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
    return data.count
}

func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
    return 1
}

func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
    return data[row]
}

func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
    NSUserDefaults.standardUserDefaults().setObject(data[row], forKey: "selected")
}

}

Thanks for the help!!I got it now. – Thiha Aung Feb 29 '16 at 20:10 — Thiha Aung, Feb 29 '16 at 20:10

score 13 · Accepted Answer · answered Feb 29 '16 at 19:52

13

UIPickerView api allow you to select row in any component in code:

func selectRow(_ row: Int,
   inComponent component: Int,
      animated animated: Bool)

So if you stored selected indices for your picker's components just call this method for each component before you show picker again.

answered Feb 29 '16 at 19:52

Vladimir

170,431
36
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You need to put this code where you setup you picker view. Is it the problem you have? Do you save selected indices somewhere? – Vladimir Feb 29 '16 at 19:54

yesthisisjoe · Answer 3 · 2016-02-29T20:03:12.997

5

If this is for storing some kind of setting, you may want to look into using persistent storage like NSUserDefaults. When the picker is changed, save the NSUserDefaults value. Then in your viewDidLoad method you can set the picker view to the row you saved earlier.

For example, use these lines when you detect the picker view pickerView has changed to store the row in the key pickerViewValue. Put this in didSelectRow for pickerView.

let defaults = NSUserDefaults.standardUserDefaults()
defaults.setObject(row, forKey: "pickerViewRow")

Then when you load the view, use this to set the picker to the saved row:

let defaults = NSUserDefaults.standardUserDefaults()
if let pickerViewRow = defaults.stringForKey("pickerViewRow")
{
    pickerView.selectRow(pickerViewRow, inComponent: 0, animated: true)
}

edited Feb 29 '16 at 20:03

answered Feb 29 '16 at 19:53

yesthisisjoe

1,987
2
16
32

Any Example Code help is appreciated.Thanks – Thiha Aung Feb 29 '16 at 19:54
Thanks for the help! – Thiha Aung Feb 29 '16 at 20:10
in Swift 3 : let defaults = UserDefaults.standard defaults.set(row, forKey: "pickerViewRow") – user2867432 Aug 06 '17 at 19:51

score 2 · Answer 4 · answered Feb 15 '17 at 15:16

2

For Swift 3

 func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
    if(pickerView.tag==0){
        //set some global variable
    }
}

answered Feb 15 '17 at 15:16

Rishabh Dugar

606
5
16

Showing UIPickerView with selected row

4 Answers4