WML Tutorial 10: Packet Select Control (Optgroup) and complex instance
The associated Option group generates hierarchical, which may have no significance of end users, but for the producer, the Option group can provide a lot of convenience.
Related properties:
1. Title title, usually this title cannot be displayed
Example:
what OS you use now?
The above example demonstrates an application of a basic OptGroup element, because Optgroup has no variable parameters, so it can only provide limited applications.
