What Is New in .NET Framework 4.8
This release focuses on enhancing existing components rather than introducing entirely new paradigms. The updates target core runtime, Windows Forms, WPF, and the base class library for improved stability and performance.
| Category | Key Updates |
|---|---|
| Runtime and JIT | JIT64 performance improvements, NGEN image fixes |
| Windows Forms (WinForms) | High DPI and accessibility enhancements for common controls |
| Windows Presentation Foundation (WPF) | High DPI and touch interaction improvements |
| Base Class Library (BCL) | Anti-malware scan interface for files, ZIP archive improvements, new cryptography types |
| Networking | TLS 1.3 support, RSA key generation compatibility |
How did runtime and compiler performance get better?
The 64-bit JIT compiler received optimizations for specific hardware intrinsics and general code generation. This translates to faster execution for compute-intensive workloads that can leverage these instructions.
NGEN (Native Image Generation) images saw fixes for alignment issues, making them more robust. In practice, this means fewer edge-case failures when running pre-compiled native images.
What are the key WinForms accessibility updates?
High DPI support was a major focus, fixing rendering and scaling issues in numerous controls like MonthCalendar, ToolTip, and DataGridView. This ensures apps look sharp on modern high-resolution displays.
Accessibility narrations via Narrator and other screen readers were improved for controls like CheckedListBox and ComboBox. This matters because it makes applications built on this mature framework more usable for everyone.
What WPF improvements should I know about?
WPF applications benefit from better High DPI rendering, particularly for soft keyboards and touch interactions. This enhances the user experience on touch-enabled and high-resolution devices.
Data binding performance for large sets was also improved. This reduces UI lag when displaying complex data, a common pain point in data-heavy business applications.
What's new in the Base Class Library?
The AMSI (Anti-Malware Scan Interface) integration allows scanning in-memory streams before use. This is a security-centric feature for scenarios where you're evaluating potentially unsafe content.
ZIP archive methods in System.IO.Compression no longer throw exceptions for invalid entry names and handle encoding better. This makes file operations more resilient to malformed archives.
New cryptography types like AesGcm and AesCcm were introduced, providing modern authenticated encryption algorithms directly within the framework.
Are there networking and security enhancements?
Yes, .NET Framework 4.8 adds support for the TLS 1.3 protocol, enabling more secure and performant encrypted communications. This keeps framework apps aligned with modern web security standards.
RSA key generation on Windows now uses the modern Windows CNG API when the key size is 2048 bits or larger, improving compatibility with newer cryptographic standards.
FAQ
Is TLS 1.3 enabled by default in .NET Framework 4.8?
No, it is not enabled by default for backward compatibility. You must opt-in by setting the SchUseStrongCrypto registry key or configuring your application to use the system default security protocol, which may include TLS 1.3.
Do I need to recompile my application to get the JIT and NGEN improvements?
For the JIT compiler improvements, no recompilation is needed; the runtime benefits are automatic. For the NGEN image fixes, you may need to regenerate your native images to get the corrected versions.
Are the new AesGcm and AesCcm cryptography classes available for all application types?
These classes are available for applications targeting .NET Framework 4.8. However, their availability might depend on the underlying Windows OS version supporting the necessary cryptographic primitives.
How significant are the High DPI improvements for WinForms?
They are very significant for applications deployed in environments with mixed DPI monitors or high-resolution screens. It resolves long-standing rendering artifacts that previously required complex manual workarounds.
Can I use the AMSI integration to scan any data?
The AMSI interface is designed primarily to scan content that could potentially be script or executable code, like strings or memory blocks, before they are passed to an interpreter or executed. It's not a general-purpose file virus scanner.