Delegate independent tasks to specialized agents working concurrently with isolated context.
CollectionView – .NET MAUI
maui-collectionview
Guidance for implementing CollectionView in .NET MAUI apps — data display, layouts (list & grid), selection, grouping, scrolling, empty views, templates, incremental loading, swipe actions, and pull-to-refresh. USE FOR: "CollectionView", "list view", "grid layout", "data template", "item template...
SKILL.md
Full skill instructions
CollectionView – .NET MAUI
Use CollectionView for displaying scrollable lists and grids of data.
It replaces ListView and offers better performance, flexible layouts, and no ViewCell requirement.
Essential patterns
Basic setup
<CollectionView ItemsSource="{Binding Items}">
<CollectionView.ItemTemplate>
<DataTemplate x:DataType="models:Item">
<HorizontalStackLayout Padding="8" Spacing="8">
<Image Source="{Binding Icon}" WidthRequest="40" HeightRequest="40" />
<Label Text="{Binding Name}" VerticalOptions="Center" />
</HorizontalStackLayout>
</DataTemplate>
</CollectionView.ItemTemplate>
</CollectionView>
- Bind
ItemsSourceto anObservableCollection<T>so the UI updates on add/remove. - Each item template root must be a
LayoutorView— never useViewCell. - Always set
x:DataTypeonDataTemplatefor compiled bindings.
SwipeView — binding from inside DataTemplate
Commands inside a DataTemplate can't directly reach your ViewModel. Use RelativeSource AncestorType:
<SwipeItem Text="Delete"
BackgroundColor="Red"
Command="{Binding Source={RelativeSource AncestorType={x:Type viewmodels:MainViewModel}}, Path=DeleteCommand}"
CommandParameter="{Binding}" />
Pull-to-refresh
Wrap CollectionView in a RefreshView. Set IsRefreshing back to false when done:
<RefreshView IsRefreshing="{Binding IsRefreshing}"
Command="{Binding RefreshCommand}">
<CollectionView ItemsSource="{Binding Items}" />
</RefreshView>
Incremental loading (infinite scroll)
<CollectionView ItemsSource="{Binding Items}"
RemainingItemsThreshold="5"
RemainingItemsThresholdReachedCommand="{Binding LoadMoreCommand}" />
⚠️ Do NOT use with StackLayout-based ItemsLayout — it has no virtualization and triggers infinite threshold-reached events. Always use
LinearItemsLayoutorGridItemsLayout.
Performance tips
- Use
MeasureFirstItemfor uniform item sizes — significantly faster than the defaultMeasureAllItems:<LinearItemsLayout Orientation="Vertical" ItemSizingStrategy="MeasureFirstItem" /> - Always use
ObservableCollection<T>, notList<T>. Swapping aListforces a full re-render. - Update collections on the UI thread —
MainThread.BeginInvokeOnMainThread(() => Items.Add(item)).
Common gotchas
| Issue | Fix |
|---|---|
| UI doesn't update when items change | Use ObservableCollection<T>, not List<T>. |
| App crashes or blank items | Never use ViewCell — use Grid, StackLayout, or any View as template root. |
| Items disappear or layout breaks | Always update ItemsSource and the collection on the UI thread (MainThread.BeginInvokeOnMainThread). |
| Incremental loading fires endlessly | Don't use StackLayout as layout; use LinearItemsLayout or GridItemsLayout. |
| EmptyView doesn't render correctly | Wrap custom empty views in ContentView. |
| Poor scroll performance | Use MeasureFirstItem sizing strategy for uniform item sizes. |
| Selected state not visible | Add VisualState Name="Selected" to the item template root element. |
| Binding errors in SwipeView commands | Use RelativeSource AncestorType to reach the ViewModel from inside the item template. |
More Other skills
brand-guidelines
Applies Anthropic's official brand colors and typography to any sort of artifact that may benefit from having Anthropic's look-and-feel. Use it when brand colors or style guidelines, visual formatting, or company design standards apply.
theme-factory
Toolkit for styling artifacts with a theme. These artifacts can be slides, docs, reportings, HTML landing pages, etc. There are 10 pre-set themes with colors/fonts that you can apply to any artifact that has been creating, or can generate a new theme on-the-fly.
internal-comms
A set of resources to help me write all kinds of internal communications, using the formats that my company likes to use. Claude should use this skill whenever asked to write some sort of internal communications (status reports, leadership updates, 3P updates, company newsletters, FAQs, incident reports, project updates, etc.).
Fundamental design principles for writing maintainable, testable Python code.
responsive-design
Modern responsive layouts using container queries, fluid typography, CSS Grid, and mobile-first strategies.
Generate Playwright tests from scenarios using interactive browser exploration and validation.
Automated website exploration and test case generation using Playwright.
Modern React state management with Redux Toolkit, Zustand, Jotai, and React Query for every state category.
gdpr-data-handling
GDPR-compliant data handling with consent management, data subject rights, and privacy controls.
Python error handling patterns including input validation, exception hierarchies, and partial failure handling. Use when implementing validation logic, designing exception strategies, handling batch processing failures, or building robust APIs.
refactor-plan
Detailed multi-file refactor planning with safety checks and rollback guidance.
