reactiveui · glennawatson · Jan 12, 2026 · Jan 3, 2026 · Jan 3, 2026
diff --git a/README.md b/README.md
@@ -24,7 +24,7 @@ This documentation covers using ReactiveUI Source Generators to simplify and enh
 
 ReactiveUI Source Generators automatically generate ReactiveUI objects to streamline your code. These Source Generators are designed to work with ReactiveUI V19.5.31+ and support the following features:
 
-- `[Reactive]` With field and access modifiers, partial property support (C# 13 Visual Studio Version 17.12.0), partial properties with initializer support (C# preview only)
+- `[Reactive]` With field and access modifiers, partial property support (C# 13 Visual Studio Version 17.12.0), partial properties with initializer support (C# 14+/preview only)
 - `[Reactive(SetModifier = AccessModifier.Protected)]` With field and access modifiers, (Not Required for partial properties, configure set accessor with the property declaration).
 - `[Reactive(Inheritance = InheritanceModifier.Virtual)]` With field and access modifiers. This will generate a virtual property.
 - `[Reactive(UseRequired = true)]` With field and access modifiers. This will generate a required property, (Not Required for partial properties, use required keyword for property declaration).

diff --git a/src/ReactiveUI.SourceGenerators.Roslyn/AttributeDefinitions.cs b/src/ReactiveUI.SourceGenerators.Roslyn/AttributeDefinitions.cs
@@ -164,7 +164,7 @@ internal sealed class ReactiveCommandAttribute : global::System.Attribute
     /// <value>
     /// The reactive attribute.
     /// </value>
-#if ROSYLN_412
+#if ROSYLN_412 || ROSYLN_500
     public static string ReactiveAttribute => $$"""
 // Copyright (c) {{DateTime.Now.Year}} .NET Foundation and Contributors. All rights reserved.
 // Licensed to the .NET Foundation under one or more agreements.
@@ -275,7 +275,7 @@ public ReactiveAttribute(params string[] alsoNotify)
 #endif
 
     public const string ObservableAsPropertyAttributeType = "ReactiveUI.SourceGenerators.ObservableAsPropertyAttribute";
-#if ROSYLN_412
+#if ROSYLN_412 || ROSYLN_500
     public static string ObservableAsPropertyAttribute => $$"""
 // Copyright (c) {{DateTime.Now.Year}} .NET Foundation and Contributors. All rights reserved.
 // Licensed to the .NET Foundation under one or more agreements.

diff --git a/...tors.Roslyn/ObservableAsProperty/ObservableAsPropertyGenerator{FromObservable}.Execute.cs b/...tors.Roslyn/ObservableAsProperty/ObservableAsPropertyGenerator{FromObservable}.Execute.cs
@@ -159,7 +159,7 @@ public sealed partial class ObservableAsPropertyGenerator
 
                 isNullableType = propertySymbol.Type is INamedTypeSymbol nullcheck && nullcheck.TypeArguments[0].IsNullableType();
             }
-#if ROSYLN_412
+#if ROSYLN_412 || ROSYLN_500
             else
             {
                 if (!propertySymbol.IsPartialDefinition || propertySymbol.IsStatic)

diff --git a/src/ReactiveUI.SourceGenerators.Roslyn/Reactive/ReactiveGenerator.Execute.cs b/src/ReactiveUI.SourceGenerators.Roslyn/Reactive/ReactiveGenerator.Execute.cs
@@ -26,7 +26,7 @@ public sealed partial class ReactiveGenerator
     internal static readonly string GeneratorName = typeof(ReactiveGenerator).FullName!;
     internal static readonly string GeneratorVersion = typeof(ReactiveGenerator).Assembly.GetName().Version.ToString();
 
-#if ROSYLN_412
+#if ROSYLN_412 || ROSYLN_500
     private static Result<PropertyInfo?>? GetPropertyInfo(in GeneratorAttributeSyntaxContext context, CancellationToken token)
     {
         using var builder = ImmutableArrayBuilder<DiagnosticInfo>.Rent();
@@ -123,11 +123,17 @@ public sealed partial class ReactiveGenerator
 
         var typeNameWithNullabilityAnnotations = propertySymbol.Type.GetFullyQualifiedNameWithNullabilityAnnotations();
         var fieldName = propertySymbol.GetGeneratedFieldName();
-
+#if ROSYLN_500
+        if (context.SemanticModel.Compilation is CSharpCompilation compilation && compilation.LanguageVersion >= LanguageVersion.CSharp14)
+        {
+            fieldName = "field";
+        }
+#else
         if (context.SemanticModel.Compilation is CSharpCompilation compilation && compilation.LanguageVersion == LanguageVersion.Preview)
         {
             fieldName = "field";
         }
+#endif
 
         var propertyName = propertySymbol.Name;
 
@@ -176,14 +182,14 @@ public sealed partial class ReactiveGenerator
     }
 #endif
 
-    /// <summary>
-    /// Gets the observable method information.
-    /// </summary>
-    /// <param name="context">The context.</param>
-    /// <param name="token">The token.</param>
-    /// <returns>
-    /// The value.
-    /// </returns>
+        /// <summary>
+        /// Gets the observable method information.
+        /// </summary>
+        /// <param name="context">The context.</param>
+        /// <param name="token">The token.</param>
+        /// <returns>
+        /// The value.
+        /// </returns>
     private static Result<PropertyInfo?>? GetVariableInfo(in GeneratorAttributeSyntaxContext context, CancellationToken token)
     {
         using var builder = ImmutableArrayBuilder<DiagnosticInfo>.Rent();

diff --git a/src/ReactiveUI.SourceGenerators.Roslyn/Reactive/ReactiveGenerator.cs b/src/ReactiveUI.SourceGenerators.Roslyn/Reactive/ReactiveGenerator.cs
@@ -32,7 +32,7 @@ public void Initialize(IncrementalGeneratorInitializationContext context)
         });
 
         RunReactiveFromField(context);
-#if ROSYLN_412
+#if ROSYLN_412 || ROSYLN_500
         RunReactiveFromProperty(context);
 #endif
     }
@@ -87,7 +87,7 @@ private static void RunReactiveFromField(IncrementalGeneratorInitializationConte
         });
     }
 
-#if ROSYLN_412
+#if ROSYLN_412 || ROSYLN_500
     private static void RunReactiveFromProperty(IncrementalGeneratorInitializationContext context)
     {
         // Gather info for all annotated variable with at least one attribute.

diff --git a/src/ReactiveUI.SourceGenerators.Roslyn5000/ReactiveUI.SourceGenerators.Roslyn5000.csproj b/src/ReactiveUI.SourceGenerators.Roslyn5000/ReactiveUI.SourceGenerators.Roslyn5000.csproj
@@ -0,0 +1,41 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>$(RoslynTfm)</TargetFramework>
+    <Nullable>enable</Nullable>
+    <LangVersion>latest</LangVersion>
+    <EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
+    <IsRoslynComponent>true</IsRoslynComponent>
+    <EnforceExtendedAnalyzerRules>true</EnforceExtendedAnalyzerRules>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <IncludeBuildOutput>false</IncludeBuildOutput>
+    <DevelopmentDependency>true</DevelopmentDependency>
+    <IsPackable>false</IsPackable>
+
+    <PackageDescription>A MVVM framework that integrates with the Reactive Extensions for .NET to create elegant, testable User Interfaces that run on any mobile or desktop platform. This is the Source Generators package for ReactiveUI</PackageDescription>
+    <AssemblyName>ReactiveUI.SourceGenerators</AssemblyName>
+    <DefineConstants>$(DefineConstants);ROSYLN_500</DefineConstants>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp" PrivateAssets="all" VersionOverride="5.0.0" />
+    <PackageReference Include="Microsoft.CodeAnalysis.Common" PrivateAssets="all" VersionOverride="5.0.0" />
+    <PackageReference Include="Microsoft.CodeAnalysis.Workspaces.Common" PrivateAssets="all" VersionOverride="5.0.0" />
+    <PackageReference Include="Microsoft.CodeAnalysis" PrivateAssets="all" VersionOverride="5.0.0" />
+    <PackageReference Include="Microsoft.CodeAnalysis.CSharp.Workspaces" PrivateAssets="all" VersionOverride="5.0.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <InternalsVisibleTo Include="ReactiveUI.CodeFixes" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Compile Include="..\ReactiveUI.SourceGenerators.Roslyn\**\*.cs" LinkBase="Shared" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <AdditionalFiles Include="..\ReactiveUI.SourceGenerators.Roslyn\AnalyzerReleases.Shipped.md" />
+    <AdditionalFiles Include="..\ReactiveUI.SourceGenerators.Roslyn\AnalyzerReleases.Unshipped.md" />
+  </ItemGroup>
+
+</Project>
diff --git a/src/ReactiveUI.SourceGenerators.sln b/src/ReactiveUI.SourceGenerators.sln
@@ -1,6 +1,6 @@
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio Version 17
-VisualStudioVersion = 17.10.35027.167
+# Visual Studio Version 18
+VisualStudioVersion = 18.1.11312.151 d18.0
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "SolutionConfig", "SolutionConfig", "{F29AF2F3-DEC8-58BC-043A-1447862C832D}"
 	ProjectSection(SolutionItems) = preProject
@@ -38,6 +38,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ReactiveUI.SourceGenerators
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ReactiveUI.SourceGenerators.Roslyn4120", "ReactiveUI.SourceGenerators.Roslyn4120\ReactiveUI.SourceGenerators.Roslyn4120.csproj", "{BF121262-7F30-4EC0-9F03-324AC3B834B8}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ReactiveUI.SourceGenerators.Roslyn5000", "ReactiveUI.SourceGenerators.Roslyn5000\ReactiveUI.SourceGenerators.Roslyn5000.csproj", "{93D7DF9A-791F-4DCF-ADBA-95BFAF3E98A7}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -84,6 +86,10 @@ Global
 		{BF121262-7F30-4EC0-9F03-324AC3B834B8}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{BF121262-7F30-4EC0-9F03-324AC3B834B8}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{BF121262-7F30-4EC0-9F03-324AC3B834B8}.Release|Any CPU.Build.0 = Release|Any CPU
+		{93D7DF9A-791F-4DCF-ADBA-95BFAF3E98A7}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{93D7DF9A-791F-4DCF-ADBA-95BFAF3E98A7}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{93D7DF9A-791F-4DCF-ADBA-95BFAF3E98A7}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{93D7DF9A-791F-4DCF-ADBA-95BFAF3E98A7}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

diff --git a/src/ReactiveUI.SourceGenerators/ReactiveUI.SourceGenerators.csproj b/src/ReactiveUI.SourceGenerators/ReactiveUI.SourceGenerators.csproj
@@ -29,6 +29,7 @@
 
   <ItemGroup>
     <ProjectReference Include="..\ReactiveUI.SourceGenerators.Analyzers.CodeFixes\ReactiveUI.SourceGenerators.Analyzers.CodeFixes.csproj" />
+    <ProjectReference Include="..\ReactiveUI.SourceGenerators.Roslyn5000\ReactiveUI.SourceGenerators.Roslyn5000.csproj" ReferenceOutputAssembly="false" />
     <ProjectReference Include="..\ReactiveUI.SourceGenerators.Roslyn4120\ReactiveUI.SourceGenerators.Roslyn4120.csproj" ReferenceOutputAssembly="false" />
     <ProjectReference Include="..\ReactiveUI.SourceGenerators.Roslyn480\ReactiveUI.SourceGenerators.Roslyn480.csproj" ReferenceOutputAssembly="false" />
   </ItemGroup>
@@ -37,5 +38,6 @@
   <ItemGroup>
     <None Include="..\ReactiveUI.SourceGenerators.Roslyn480\bin\$(Configuration)\netstandard2.0\ReactiveUI.SourceGenerators.dll" PackagePath="analyzers\dotnet\roslyn4.8\cs" Pack="true" Visible="false" />
     <None Include="..\ReactiveUI.SourceGenerators.Roslyn4120\\bin\$(Configuration)\netstandard2.0\ReactiveUI.SourceGenerators.dll" PackagePath="analyzers\dotnet\roslyn4.12\cs" Pack="true" Visible="false" />
+    <None Include="..\ReactiveUI.SourceGenerators.Roslyn5000\\bin\$(Configuration)\netstandard2.0\ReactiveUI.SourceGenerators.dll" PackagePath="analyzers\dotnet\roslyn5.0\cs" Pack="true" Visible="false" />
   </ItemGroup>
 </Project>