maui: Instructions file for GitHub Copilot

.github/instructions/collectionview-windows.instructions.md

maui collectionview-windows.instructions.md is an instructions file for GitHub Copilot from dotnet/maui. It costs 333 tokens per session, scanned A, original, MIT.

Project instructions for the Windows implementation of .NET MAUI CollectionView, a cross-platform control that displays a scrollable list or grid of items. They explain how it maps to Windows UI components.

In plain words
What is it for?
Use them when changing Windows CollectionView item handling, data-source notifications, selection modes, layouts, dimensions, or cross-platform behavior.
Why use it?
They help preserve selection, scrolling, native styling, layout behavior, and correct updates when the item list changes.

Instructions file for GitHub Copilot

Written for GitHub Copilot: a Copilot instructions file.

This is dotnet/maui's own configuration. It tells GitHub Copilot how to work on maui itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything maui configures →

About the project

.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.

dotnet/maui · 23,322 stars · on GitHub · dot.net

Reuse

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.

Copy the file
curl -O https://raw.githubusercontent.com/dotnet/maui/main/.github/instructions/collectionview-windows.instructions.md
Clone the repo
git clone --depth 1 https://github.com/dotnet/maui

Made for: GitHub Copilot.

Wrote 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.

agentmods badge for maui collectionview-windows.instructions.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/dotnet/maui/collectionview-windows/github.svg)](https://agentmods.dev/instructions/dotnet/maui/collectionview-windows)
Your own site
<a href="https://agentmods.dev/instructions/dotnet/maui/collectionview-windows"><img src="https://agentmods.dev/badge/instructions/dotnet/maui/collectionview-windows/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.

agentmods 80×15 button for maui collectionview-windows.instructions.md

Your own site · 80×15
<a href="https://agentmods.dev/instructions/dotnet/maui/collectionview-windows"><img src="https://agentmods.dev/badge/instructions/dotnet/maui/collectionview-windows.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 333 This file is loaded in full into every session.
When invoked 333 The same file — it is already loaded in full.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00333 $0.00333
Opus 5.5 $0.00133 $0.00133
Sonnet 5.5 $0.00067 $0.00067
Haiku 4.5 $0.00033 $0.00033

Measured 1mo ago against content hash 098a6dc123bd, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

maui collectionview-windows.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.

.github/instructions/collectionview-windows.instructions.md · 27 lines

What it actually says

CollectionView — Windows (Items/ Handler)

Items/ is the ONLY Windows CollectionView implementation. Items2/ has NO Windows code.

WinUI ListView/ItemsRepeater Patterns

  • Preserve WinUI XAML styles applied via native theming — clearing a MAUI property must restore the style-applied value, not a hardcoded default
  • double.NaN is the WinUI convention for unconstrained dimensions — do not confuse with MAUI's double.PositiveInfinity
  • Use DispatcherQueue.TryEnqueue for deferred UI thread work — do not use Dispatcher.BeginInvoke

Data Source and Change Notifications

  • Handle all ObservableCollection change actions (Add, Remove, Replace, Move, Reset) with range-scoped updates
  • Avoid full source refresh (NotifyDataSetChanged equivalent) — it kills selection state and scroll position
  • Selection mode changes must propagate correctly to the native SelectionMode property

Layout Configuration

  • ItemsLayout changes require reconfiguration of the underlying panel (e.g., ItemsWrapGrid, ItemsStackPanel)
  • Verify that ItemsLayout.Span for grid layouts maps correctly to WinUI's MaximumRowsOrColumns

Cross-Platform Consistency

  • Default values for control properties must produce the same visual result as Android and iOS
  • Event firing order (selection changed, scrolled) should match other platforms for the same user interaction
Changes

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.

  1. 1mo ago First seen · 27 lines · 333 tokens per session scan A 098a6dc123bd

Subscribe to this mod's changes

maui collectionview-windows.instructions.md is an instructions file published in the GitHub repository dotnet/maui (23,322 stars, last pushed today), licensed MIT. It adds 333 tokens to every session, about $0.0013 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.