Virtual keyword in EF Core: .NET 10, ILazyLoader and explicit loading samples

[vladimir-pecanac-main]

Sample update for the article "Why EF Core Lazy Loading Needs Virtual Navigation Properties" (https://code-maze.com/efcore-why-do-we-use-the-virtual-keyword-for-class-properties/).

Folder: dotnet-efcore/VirtualKeywordInEFCore only.

• Both projects retargeted from net8.0 to net10.0.
• Microsoft.EntityFrameworkCore, .Proxies and .Sqlite 8.0.2 to 10.0.12; Microsoft.EntityFrameworkCore.Abstractions 10.0.12 added explicitly for ILazyLoader.
• Tests: Microsoft.NET.Test.Sdk 18.10.1, xunit 2.9.3, xunit.runner.visualstudio 4.0.0, coverlet.collector 10.1.0 (newest stable on NuGet, queried 2026-10-04).
• Removed the dead null check after First() in LoadData(); LoadDataWithLazyLoading() keeps its null check and ?. uses unchanged, so the article's debugger screenshot (Program.cs lines 36 to 57) still matches. Book.Author and BookLazy.Author initialised with null! (1 build warning now, the pre-existing CS8602 in LoadDataWithLazyLoading(); 3 before).
• Added AuthorInjected, BookInjected and DataContextInjected: lazy loading through an injected ILazyLoader with no virtual members and no proxy type.
• Added an explicit loading demo with Entry(...).Collection(...).Load().
• Two new tests: the injected entity lazy-loads its books while staying AuthorInjected, and explicit loading fills an empty collection.

Local run: SDK 10.0.302, runtime 10.0.10. Build 1 warning (CS8602, pre-existing), 0 errors. dotnet test: Passed 5, Failed 0. No vulnerable packages (direct or transitive).