How to detect changes on UIPickerView?

Question

I want to detect changes of UIPickerView value.

If UIPickerView respond to addTarget I used a code like this:

-(void) valueChange:(id)sender {
    change = YES;
} 

UIPickerView *questionPicker = [[UIPickerView alloc] init]; 
[questionPicker addTarget:self action:@selector(valueChange:) forControlEvents:UIControlEventValueChanged];

How can I do same things but in a correct way ?

Answer 1

If you look at the UIPickerViewDelegate it has:

- (void)pickerView:(UIPickerView *)pickerView didSelectRow:(NSInteger)row inComponent:(NSInteger)component

Simply set your picker views delegate and implement this.

Answer 2

UIPickerViewDelegate has pickerView:didSelectRow:inComponent:

Answer 3

Better override this function

public override func selectedRow(inComponent component: Int) -> Int {
  let index = super.selectedRow(inComponent: component)
  //call closure or delegate as you want
  return index
}

in UIPickerView class to observe changing in realtime.