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 [UIPickerViewDataSource numberOfComponentsInPickerView:]
En dan, zoals Hitman zei, [UIPickerView reloadAllComponents]
.
More details can be found at Apple's documentation for UIPickerViewDelegate and UIPickerViewDataSource