.NET 10 Preview 4 Release: Microsoft released the fourth preview of.NET 10 with enhancements across multiple frameworks and technologies.

• ASP.NET Core: Introduced a new JSON Patch implementation using System.Text.Json with improved performance and reduced memory use. Supports minimal API validation for record types and generating OpenAPI schemas programmatically. Has improved XML documentation integration.
• Blazor: Added a new NotFound method in NavigationManager to signal missing pages during rendering. Aligned navigation behavior during static server-side rendering with interactive scenarios. Offers detailed diagnostic capabilities for the WebAssembly runtime with some trade-offs. Extended JavaScript interop with new APIs and support for referencing JavaScript functions. Benefits from preloading static framework assets and improved asset handling.
• .NET MAUI: Brings improvements across multiple platforms like nullable support in date and time pickers and enhanced media picking.
• WPF: Has refined Fluent theme styling for text-based controls and improved message boxes and clipboard API. Achieved significant performance gains through code cleanup. Acknowledges known issues with TextBox and DatePicker under Fluent System theme mode.
• Entity Framework Core: Supports full-text search and hybrid search on Azure Cosmos DB and vector similarity search with expanded capabilities.
• Other: Improves WebApplicationFactory testing with Kestrel, enhances OpenAPI.NET support, renames APIs for consistency, and refines EF Core SQL translation and performance.