.NET MAUI is a C# and XAML framework for building native mobile and desktop applications from one shared codebase. Developers use it to create apps for Android, iOS, iPadOS, macOS, and Windows. The catalogue entries provide skills, instructions, and agents for working with .NET MAUI.
Borrowing it
Nothing to install: this file belongs to dotnet/maui. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/dotnet/maui/main/.github/instructions/collectionview-ios.instructions.mdgit clone --depth 1 https://github.com/dotnet/mauiWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/instructions/dotnet/maui/collectionview-ios)<a href="https://agentmods.dev/instructions/dotnet/maui/collectionview-ios"><img src="https://agentmods.dev/badge/instructions/dotnet/maui/collectionview-ios/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/dotnet/maui/collectionview-ios"><img src="https://agentmods.dev/badge/instructions/dotnet/maui/collectionview-ios.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00460 | $0.00460 |
| Opus 5.5 | $0.00184 | $0.00184 |
| Sonnet 5.5 | $0.00092 | $0.00092 |
| Haiku 4.5 | $0.00046 | $0.00046 |
Grade A, and why
maui collectionview-ios.instructions.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
CollectionView — iOS/MacCatalyst (Items2/ Handler)
New iOS/MacCatalyst work targets Items2/. Items/iOS/ is deprecated. See
collectionview-handler-detection.instructions.mdfor the full platform→handler mapping.
UICollectionView Cell Measurement
- Scope cell layout invalidation to the affected cell — avoid
InvalidateLayout()on the entire collection for single-cell changes - Custom
UICollectionViewCellsubclasses should handleMeasureInvalidatedonly when the hosted MAUI control actually needs remeasuring - Cell sizing must stay in sync between the measure pass and the layout pass — out-of-sync causes visual glitches
UICollectionViewCompositionalLayout
- Layout configuration must match the
ItemsLayoutspecification (Linear, Grid, or custom) ItemsLayoutproperty changes require full layout reconfiguration — partial updates leave stale section configuration- Group header/footer template changes must invalidate the correct section scope, not the entire layout
Memory Management
- Use static callback patterns to avoid retain cycles between cells and their hosting handler
- Remove
NSNotificationCenterobservers inDisconnectHandler - Weak references for long-lived observers of short-lived cells — cells are recycled and reused
Regression Patterns
- Test across empty collection, single item, many items, and with grouping — a fix for one layout scenario routinely breaks another
Items/ iOS (Deprecated)
- Files in
Handlers/Items/*.iOS.csare deprecated — prefer Items2/ for new work - Only modify Items/ iOS code for explicit legacy maintenance or backward-compatibility fixes
Platform file extension rules (
.ios.csvs.maccatalyst.cscompilation targets) are defined incopilot-instructions.md§ Platform-Specific File Extensions. See alsocollectionview-handler-detection.instructions.mdfor which handler directory to target per platform.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 35 lines · 460 tokens per session scan A 0ae0ee467746
maui collectionview-ios.instructions.md is an instructions file published in the GitHub repository dotnet/maui (23,322 stars, last pushed today), licensed MIT. It adds 460 tokens to every session, about $0.0018 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other instructions, from other repositories
plan-forge swiftui.instructions.md
SwiftUI patterns — state management, navigation, async data loading, previews.
plan-forge database.instructions.md
Database patterns for .NET — Dapper/EF Core 10, parameterized queries, migration strategy.
plan-forge naming.instructions.md
Azure naming conventions — Microsoft CAF abbreviations, constraints, uniqueness, tagging.
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).