是否有像scrollviewDidScroll这样的uipickerview委托方法？

I have a customized UIPickerview and I do not want to use a datepicker. I want to implement the feature where when a user scrolls down/up the hours, the AM/PM component switches while the hour is scrolling. This means that I need to switch it before pickerView didSelectRow is called. Is there a way to do this?I have a customized UIPickerview and I do not w