UWP-to-WinUI 3 migration reference. Maps legacy UWP APIs to correct Windows App SDK equivalents with before/after code snippets. Covers namespace changes, threading (CoreDispatcher to DispatcherQueue), windowing (CoreWindow to AppWindow), dialogs, pickers, sharing, printing, background tasks, and the most common Copilot code generation mistakes.
Install
npx skills add github/awesome-copilot --skill winui3-migration-guidenpx skills add github/awesome-copilot --skill winui3-migration-guide -a claude-code -gnpx skills add github/awesome-copilot --skill winui3-migration-guide -a codex -ggemini skills install https://github.com/github/awesome-copilot.git --path skills/winui3-migration-guidegh skill install github/awesome-copilot winui3-migration-guidegit clone --depth 1 https://github.com/github/awesome-copilot /tmp/github__awesome-copilot
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/github__awesome-copilot/skills/winui3-migration-guide ~/.claude/skills/winui3-migration-guide # Claude Code
cp -R /tmp/github__awesome-copilot/skills/winui3-migration-guide ~/.agents/skills/winui3-migration-guide # Codex, Cursor, Gemini CLI, Copilot, OpenCode