ILSpy 9.x is based on .NET 8.0. All artifacts except the self-contained distribution are built framework-dependent, which means .NET 8.0 must be installed prior to starting ILSpy.

Breaking Changes in ICSharpCode.Decompiler

• Remove IsRef, IsOut and IsIn flags from IParameter
• Replace ParameterModifiers with ReferenceKind.

New Language Features

• Update pattern detection to Roslyn 4.11.0
• Support types that provide DisposeAsync without implementing IAsyncDisposable.
• Add support for C# 12 primary constructors.
• Add support for C# 12 'ref readonly' parameters

Contributions

• Add smooth scrolling to settings panels and DecompilerTextView (see #3244 by @tom-englert)
• Decompiler Settings: Checkbox in group header does not reflect state of the group (see #3252 by @tom-englert)
• Various WPF-related refactorings by @tom-englert (see #3257, #3266, #3274, #3283, #3285, #3291, #3292, #3294, #3295, #3297, #3298, #3299, #3302, #3308 and #3314)
• Ignore empty version directories of dotnet (#3265 by @Herrmel)
• Fix Derived Types Node always being empty (#3280 by @Applesauce314)

Enhancements

• Allow running tests on ARM64 (see #3231)
• Alow collecting analyzers annotated with ExportAnalyzerAttribute (see #3239)
• Fix #3237: Use ref readonly locals for readonly.ldelema
• Fix #3001: Support new resources format in ResourcesFile/ResXResourceWriter
• Fix #3134: Include newobj, initobj and call instructions in TypeInstantiatedByAnalyzer
• Fix #3089: Add comment regarding .constraint prefix expressed as cast in C#

Bug fixes

• Fix #3209: Ensure using directives are added for extension methods in higher level patterns such as: foreach -> GetEnumerator(), collection initializer -> Add() and deconstruction -> Deconstruct().
• Fix #3255: Ignore exceptions while decoding sequence point blobs.
• Fix #2166: Unnecessary uint casts/conversions for certain bitwise operations
• Fix #3310: Filter out copy-constructor only if it's an actual record type.

And many other fixes, for a full list click here.