Eerst, wanneer die bepaalde rij is geselecteerd (die u kunt detecteren via de
[UIPickerViewDelegate: pickerView: didSelectRow: inComponent:] methode)
You'd have to modify your UIPickerViewDataSource to reflect that a new column is added by incrementing the value returned by
En dan, zoals Hitman zei,
[UIPickerView reloadAllComponents] .
More details can be found at Apple's documentation for UIPickerViewDelegate and UIPickerViewDataSource