WinForms conventions

WinForms is an immediate-mode, control-tree desktop UI. The realistic work is maintenance and modernization of line-of-business apps, not greenfield, so this skill floors new work at .NET 8 / C# 12 while treating .NET Framework 4.8 as a supported-but-frozen maintenance surface - fully serviced, but no new WinForms features land there. The conventions below are the same whichever runtime you are on; the version-specific mechanics live in the references.

Load the version reference for the concrete mechanics:

• .NET Framework 4.8 (the frozen world) -> references/net-framework-48.md
• .NET 8 / 9 / 10 (the strategic target) -> references/modern-net.md

Out of scope, by design: the async / nullable / mapping baseline -> csharp; deeper MVP, command, observer, and memento orchestration -> csharp-design-patterns; test framework + UI-automation mechanics -> dotnet-testing; the upgrade safety playbook (baseline, staged, rollback) -> dotnet-migrate; SDK-style project shape and packaging -> dotnet-project-setup; general managed-memory profiling -> dotnet-diagnostics; general perf and type design -> dotnet-performance; a paired Windows-Service half -> dotnet-hosted-services.