Xamarin.Forms - Expandable ListView With A Sub ListView MVVM Pattern

In mobile applications we often have lists to display, this is easy only if the list contains simple and not complex structure. This article demonstrates how we create a complex Expandable ListView with a sub ListView in Xamarin.Forms.. This Expandable List allows user to Expand and Collapse items via a simple click. We have a List of Hotels each hotel contains a list of rooms. One click on a hotel will display its rooms while a double click will collapse it.

source https://www.c-sharpcorner.com/article/xamarin-forms-expandable-listview-with-a-sub-listview-mvvm-pattern/