How to force UIPickerView.selectRow call didSelectRow method?

Question

Is it possible to call func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) method, when running UIPickerView.selectRow(4, inComponent: 0, animated: false)

or what is right way to archive this?

my implementation

let pickerView = UIPickerView()

pickerView.delegate = self
pickerView.dataSource = self
pickerView.selectRow(0, inComponent: 0, animated: false)
textField.inputView = pickerView

func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {

}

Answer 1

This to select the row

 self.yourPickerViewName.selectRow(2, inComponent: 0, animated: true)

and this to trigger the method

 self.pickerView(self.yourPickerViewName, didSelectRow: 2, inComponent: 0)

Combine them to simulate user action

Answer 2

It is definitely not a bug that func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) is not called when you programatically select a row. Documentation says:

Called by the picker view when the user selects a row in a component.

It's a delegate method which gets called only when a user selects a row. So naturally it won't get called if you select a row like this:

pickerView.selectRow(0, inComponent: 0, animated: false) 

The hack in your accepted answer works, but it's not good practice to call delegate methods from your view controller. I suggest you to create another method which will do what you want when a row is selected by user or programatically:

e.g.

func doStuff(for row: Int, component: Int) {
    // Do your stuff here
}

then in your delegate method:

func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
    doStuff(for: row, component: component)
}

and when you select a row programatically:

pickerView.selectRow(0, inComponent: 0, animated: false)
doStuff(for: 0, component: 0)

If you need to do something with the pickerView in the doStuff method you can add another parameter and pass it along when you call it, or access pickerView variable directly.