All skills
openai avatar

/winui-app

@c207989 official
by openaiopenai/skills28k stars
1,891

Bootstrap, develop, and design modern WinUI 3 desktop applications with C# and the Windows App SDK using official Microsoft guidance, WinUI Gallery patterns, Windows App SDK samples, and CommunityToolkit components. Use when creating a brand new app, preparing a machine for WinUI, reviewing, refactoring, planning, troubleshooting, environment-checking, or setting up WinUI 3 XAML, controls, navigation, windowing, theming, accessibility, responsiveness, performance, deployment, or related Windows app design and development work.

Use this Skill: https://skilld.dev/gh/openai/skills/winui-app

This session only. Nothing lands on disk.

referencestesting-debugging-and-review-checklists.md

≈1.1k tokens on demand. Your agent reads this file only when SKILL.md points to it.

What This Reference Is For

Use this file for final review passes, debugging sessions, and "what should I verify before I call this done?" prompts.

Required Verification Loop

  • Build after each meaningful edit, not only at the end.
  • Run the app after changes when the user asked for it or when startup-sensitive files changed.
  • Verify actual launch instead of assuming success from a spawned process.
  • If the app fails before showing a window, debug the startup path before continuing feature work.

Design Review Checklist

  • Shell and navigation are simple and predictable.
  • NavigationView still reads like standard WinUI shell chrome unless the product explicitly calls for branded pane content or custom shell composition.
  • Layout stays usable when the window is narrow.
  • Layout has been checked at more than one breakpoint, including a genuinely phone-like width when the app can be resized that far.
  • Collection pages with mixed scroll regions have been checked at runtime so shelves still render in the intended direction and do not collapse into a single vertical column.
  • Theme, contrast, hierarchy, and interactive state visibility hold up in both light and dark mode, and typography and iconography still feel native to Windows.
  • Command placement and hierarchy are clear.
  • Default WinUI surfaces and control templates carry most of the layout instead of a custom border/card system.
  • Search and filter workflows avoid redundant controls when live local filtering would be clearer.
  • At narrow and phone widths, nonessential controls are simplified, hidden, or moved behind shell affordances instead of merely compressed.

Code Review Checklist

  • App structure is coherent and scalable.
  • Resource dictionaries and styles are centralized where they should be.
  • Platform controls are preferred over unnecessary custom control work.
  • New dependencies are justified.
  • The packaging model matches the startup, storage, and launch code.
  • The app builds cleanly from the workflow the user will actually use.

Accessibility Checklist

  • Keyboard-only flow works end to end.
  • Focus states are visible and sensible.
  • Automation properties are present where needed.
  • High contrast and text scaling do not break the UI.

Performance Checklist

  • No obvious UI-thread blocking work in interactive paths.
  • Large collections use an appropriate control and layout.
  • Scroll ownership is intentional for collection-heavy pages; nested GridView plus outer ScrollViewer combinations have been justified or replaced.
  • Expensive styling or template choices are justified.
  • Profiling data exists for non-obvious performance claims.

Debugging Tools

  • Use Hot Reload for fast visual iteration.
  • Use Live Visual Tree and Live Property Explorer for layout and property debugging.
  • Use WPR and WPA when diagnosing frame or responsiveness issues.
  • Reproduce resize, theme, and input-mode changes before concluding the issue is fixed.
  • When resize behavior is part of the task, verify wide, medium, and phone-width states against the running app rather than trusting the XAML structure alone.
  • When a collection page looks wrong, inspect the live tree for nested ScrollViewer ownership before rewriting the item template; the bug may be layout ownership rather than card markup.
  • Use startup exception details, debugger output, or Event Viewer when the process dies before any window appears.

Exit Criteria

  • The build succeeds from the intended local workflow.
  • The feature works on the intended machine configuration.
  • The app launches and shows the expected shell or window.
  • The app remains usable in light, dark, and high contrast.
  • Primary flows are keyboard-accessible.
  • Resize behavior, startup, and interactive responsiveness have been checked.
  • If the window can become phone-width, the shell and content have been verified there too.

Source: SKILL.md on GitHub

No alerts17d5 checks · Risk SAFE
  • Gen Agent Trust Hub17d

    This skill provides guidance and scaffolding patterns for building WinUI 3 desktop applications with the Windows App SDK. It includes standard platform configuration and setup mechanisms that leverage official Windows tools. While it executes configuration scripts to configure the local environment, these are implemented via native tools such as WinGet according to official Microsoft workflows.

  • Socket17d

    No alerts

  • Snyk17d

    Risk: LOW · No issues

  • Runlayer6mo

    5/20 files flagged

  • ZeroLeaks5mo

    Score: 93/100 · 2 sections analyzed

Signed by skilld at c207989. This ties the file your Agent reads to that commit on GitHub. It does not review the instructions.

Last checked against GitHub 2 months ago.

Activeupdated 7 months ago
  • winui
  • csharp
  • windows-app-sdk
  • desktop
  • xaml
  • visual-studio
  • winget
  • theming
  • accessibility
  • responsive-design

README badge

README badge for openai/skills/winui-app

Bootstraps and develops WinUI 3 desktop applications in C# using the Windows App SDK, with guidance for environment setup, project scaffolding, XAML patterns, controls, navigation, theming, and deployment. Use this skill when creating a new app, preparing a machine for WinUI development, or troubleshooting XAML compilation and startup issues.

Generated from the current SKILL.md.

Does this skill work with C++ or only C#?
The skill is built around C# and the Windows App SDK. C++ or C++/WinRT is mentioned only when the difference is material to the task.
Can I use this skill to set up an unpackaged app instead of a packaged one?
Yes. The skill supports both packaged and unpackaged app models. You can pass the `--unpackaged` flag to `dotnet new winui`, or the skill will default to packaged for Store-like workflows and unpackaged for CLI build-and-run loops.
What if my machine isn't ready for WinUI development yet?
The skill includes a bundled WinGet configuration (`config.yaml`) that installs Visual Studio Community 2026, enables Developer Mode, and adds the required Windows App SDK C# components. For diagnostics-only audits without machine changes, the skill provides manual verification guidance instead.
Does this skill handle third-party component libraries or only native WinUI controls?
The skill favors native WinUI controls and Fluent styling first. It uses the CommunityToolkit only when built-in controls do not cover the need cleanly, and avoids inventing custom component libraries unless you explicitly request them.

Generated from the current SKILL.md. These answers refresh after source changes.