building-winforms-applications

Structures WinForms applications with Designer-compatible patterns, proper code organization, and build/runtime compatibility. Use when creating or maintaining WinForms projects, working with Form or UserControl classes, organizing InitializeComponent vs application logic, implementing Application.Run patterns, handling Program.cs and ApplicationConfiguration, managing Application.SetHighDpiMode, working with .resx resource files, or troubleshooting Designer serialization issues. Also triggers for "WinForms project structure", "Form class organization", "Designer compatibility", "Application.Run", "Program.cs setup", and "WinForms best practices". Enhancement features (dark mode, async APIs, MVVM) are in separate skills for opt-in adoption only.

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Repository: microsoft/upgrade-agent-plugins
Last source activity: August 3, 2026 at 23:56
Detected SKILL.md language: English
Stars: 29
Forks: 4

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migrating-csharp-nullable-references

Enable nullable reference types in a C# project and systematically resolve all warnings. Use when adopting NRTs in existing codebases, performing file-by-file or project-wide nullable migration, fixing CS8602/CS8618/CS86xx warnings, annotating APIs for nullability, cleaning up null-forgiving operators, or upgrading dependencies with new nullable annotations. Also use when the user asks to "enable nullable", "turn on NRTs", "annotate for nullability", "fix nullable warnings", or "migrate to nullable reference types". DO NOT USE FOR: projects already fully migrated with zero warnings (unless auditing suppressions), fixing a handful of nullable warnings in code that already has NRTs enabled, suppressing warnings without fixing them, C# 7.3 or earlier projects. INVOKES: Get-NullableReadiness.ps1 scanner script.

2026-08-20

managing-shared-database-schema

Governs a SQL database that two hosts read and write at the same time during a side-by-side migration. Use when a legacy .NET Framework app and a new .NET app share one database, point at the same connection string, or must both stay live while the schema changes. Covers which toolchain owns schema changes, expand-then-contract (additive-only) evolution, dual-write and backfill ordering, deployment ordering, and rollback rules. Triggers for "shared database", "who runs migrations", "dual write", "zero downtime schema change", or "add a column safely". Applies to EF6, EF Core, Dapper, ADO.NET, DACPAC/SqlPackage, DbUp and Flyway, and explains how EF6's __MigrationHistory and EF Core's __EFMigrationsHistory coexist without merging. Also use before deleting a Migrations folder, before enabling Database.Migrate() at startup, or when asked whether renaming or dropping a column is safe while the old app is live.

2026-08-20

migrating-edmx-to-code-first

Migrates Entity Framework 6 EDMX-based models (Database-First/Model-First) to EF Core Code-First. Use when upgrading projects containing .edmx files, .Context.tt templates, EntityClient connection strings, or ObjectContext references. Triggers for "migrate EDMX", "convert EDMX to code first", "EF6 to EF Core", "remove EDMX", "database first to code first", and "scaffold DbContext". Also relevant when encountering EntitySQL, EntityObject, or ObjectSet patterns during .NET modernization.

2026-08-20

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name	building-winforms-applications
description	Structures WinForms applications with Designer-compatible patterns, proper code organization, and build/runtime compatibility. Use when creating or maintaining WinForms projects, working with Form or UserControl classes, organizing InitializeComponent vs application logic, implementing Application.Run patterns, handling Program.cs and ApplicationConfiguration, managing Application.SetHighDpiMode, working with .resx resource files, or troubleshooting Designer serialization issues. Also triggers for "WinForms project structure", "Form class organization", "Designer compatibility", "Application.Run", "Program.cs setup", and "WinForms best practices". Enhancement features (dark mode, async APIs, MVVM) are in separate skills for opt-in adoption only.
metadata	{"discovery":"lazy","traits":"(.NET\|CSharp\|VisualBasic\|DotNetCore) & WindowsForms"}

WinForms Development Guide

Modern .NET WinForms development for Designer-compatible applications with proper separation of concerns between Designer-generated code and application logic.

When to Use This Skill

Use this skill when:

Creating new or maintaining existing WinForms projects or WinForms control libraries
Developing Forms or UserControls to be compatible with the WinForms Designer
Modernizing legacy WinForms applications or even legacy VB6 applications
Setting up solution structures and configuration with enough evidence for using the WinForms projects as the UI stack.

Related Skills

For specialized topics, see:

Detailed Guidance

Read Detailed guide for comprehensive patterns, examples, and troubleshooting.

For opt-in enhancement features (dark mode, async APIs), see the focused guides dark mode and async APIs - these are only applied when explicitly requested or invoked by the winforms-feature-adoption scenario.

Workflow

Confirm the scenario matches the triggers in this skill.
Apply the baseline pattern from this file.
Read Detailed guide for advanced or edge-case handling.
Validate changes with an actual build and runtime check.

building-winforms-applications

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More from this repository

More from this repository

WinForms Development Guide

When to Use This Skill

Related Skills

Detailed Guidance

Workflow

WinForms Development Guide

When to Use This Skill

Related Skills

Detailed Guidance

Workflow