Fix code squigglies and move snippets

[gewarren]

Fixes #42459

---

Internal previews

📄 File	🔗 Preview link
docs/standard/events/how-to-raise-and-consume-events.md	How to: Raise and consume events
docs/standard/events/index.md	Handle and raise events

[Copilot]

Pull request overview

This pull request addresses issue #42459 by fixing compiler warnings related to nullable EventHandler declarations and relocating code snippets to a more appropriate directory structure.

Changes:

• Adds nullable annotations to EventHandler declarations in C# examples to resolve CS8618 warnings
• Moves Visual Basic and C# code snippets from samples/snippets to docs/standard/events/snippets/raise-consume directory
• Updates markdown documentation to reference the new snippet locations and improves title casing
• Modernizes C# code with primary constructors, target-typed new expressions, and nullable-aware patterns
• Updates target framework from net8.0 to net10.0

Reviewed changes

Copilot reviewed 15 out of 19 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
docs/standard/events/how-to-raise-and-consume-events.md	Updates snippet paths, applies sentence case to title, fixes xref format for generic EventHandler
docs/standard/events/snippets/raise-consume/csharp/*.cs	Adds nullable event handlers, modernizes syntax, moves from old location
docs/standard/events/snippets/raise-consume/csharp/project.csproj	Updates target framework to net10.0
docs/standard/events/snippets/raise-consume/vb/*.vb	Refactors to use underscored field naming, wraps in namespaces, moves from old location
docs/standard/events/snippets/raise-consume/vb/project.vbproj	New VB project file targeting net10.0 with Library output type
samples/snippets/visualbasic/VS_Snippets_CLR/eventsoverview/vb/*.vb	Deletes old VB snippet files
docs/standard/events/snippets/raise-consume/csharp/eventsoverview/*	Adds Visual Studio IDE cache and binary files (should not be committed)

Comments suppressed due to low confidence (1)

docs/standard/events/snippets/raise-consume/csharp/project.csproj:4

• The target framework is set to net10.0, but .NET 10 has not been released yet (as of February 2026). The latest stable .NET version is .NET 9. Using a preview or unreleased version in documentation code samples can cause build failures for users trying to run the examples. Consider using net9.0 or the latest stable version unless there's a specific requirement for .NET 10 features.

[BillWagner]

These changes LGTM @gewarren

Let's