Tag: listview

A Key is the identity half of Widget.canUpdate, the one line of framework code that decides whether an Element and its State are reused or thrown away. Here is what that means in practice, the exact list edits that corrupt state without keys, which key type to reach for, and where the key has to sit to work.

Attach a ScrollController to a ListView.builder, fire the next page when position.extentAfter drops below a prefetch threshold, and guard the fetch with isLoading, hasMore, and error flags. Full implementation plus the short-first-page trap.

For a long list, never use shrinkWrap. Use Expanded when the list is the only scrollable, and slivers (CustomScrollView) when it shares a scroll with other sections. Here is why, with a build-count benchmark.

Put a list and a grid in a single continuous scroll without nested scrollables. Use CustomScrollView with SliverList and SliverGrid, and skip the shrinkWrap trap that quietly kills performance.

Why a ListView in a Column throws 'Vertical viewport was given unbounded height', and the four fixes (Expanded, Flexible, shrinkWrap, SizedBox) with the performance trade-offs that decide which one you want.

Step-by-step migration from Xamarin.Forms 5.0 ListView to .NET MAUI 11 CollectionView for apps that already squeezed performance out of ListView. Covers cell recycling, virtualization, grouping, pull-to-refresh, context actions, selection, ItemsLayout, EmptyView, and the gotchas that bite real apps.