title: iOS UIPickerView how to get the selected row outside the delegate method
body: <p>I know the UIPickerView has this method:</p>
  
  <pre><code>- (void)pickerView:(UIPickerView *)pickerView
        didSelectRow:(NSInteger)row
         inComponent:(NSInteger)component
  </code></pre>
  
  <p>But inside this method, I want to get the selected row of other components. How on Earth can I do that?</p>