Summary

Update the target frameworks for the Microsoft.Graph.Core library and test projects to align with currently supported .NET runtimes.

Proposed Target Frameworks

Core library (Microsoft.Graph.Core.csproj):

• netstandard2.0
• netstandard2.1
• net462
• net8.0
• net10.0

Test project (Microsoft.Graph.DotnetCore.Core.Test.csproj):

• net462
• net8.0
• net10.0

Trimming test project (Microsoft.Graph.DotnetCore.Core.Trimming.csproj):

• net10.0

Changes Required

1. Update TargetFrameworks in src/Microsoft.Graph.Core/Microsoft.Graph.Core.csproj
2. Update Directory.Build.props to remove the default net6.0 MAUI target and update MAUI platform targets from net6.0-* to net8.0-*
3. Update test project TFMs from net6.0 to net462;net8.0;net10.0
4. Update trimming test project TFM from net9.0 to net10.0
5. Downgrade xunit.runner.visualstudio from 3.0.2 to 2.5.8 for net462 compatibility
6. Add conditional compilation directives in test code for net462 compatibility:
   • Replace C# range/index syntax with compatible alternatives
   • Use new HttpMethod("PATCH") instead of HttpMethod.Patch
   • Use #if NETFRAMEWORK guards for WinHttpHandler vs SocketsHttpHandler assertions
   • Use #if NETFRAMEWORK guards for using vs await using on streams
7. Fix HandlesCancellationTokenAsync test to use Assert.ThrowsAnyAsync<OperationCanceledException> to handle runtime differences across TFMs

Motivation

• net6.0 and net9.0 are end-of-life
• netstandard2.1 adds support for additional APIs (e.g., Span<T>, IAsyncDisposable)
• net8.0 is the current LTS release
• net10.0 is the latest supported runtime