Why selected index fires only once the Index of the ListItem is changed?

问题

Consider a asp:dropdownlist which fires SelectedIndexChangedEvent based on listitem index.....

But why the event doesn't fire for the same listitem index when selected again....

回答1:

Because it didn't change.

You can solve this by resetting the value after each change.

来源：https://stackoverflow.com/questions/2406681/why-selected-index-fires-only-once-the-index-of-the-listitem-is-changed