在macOS中如何配置引用.NET Framework v4.0/v4.5.2替代v2.0？

Hey there, I get where you're coming from—needing to target an older .NET Framework version for compatibility while working on macOS can feel tricky, since .NET Framework itself is Windows-only. But don't worry, we can make this work using Mono and some project configuration tweaks. Here's how:

1. Install Mono for .NET Framework Reference Assemblies #

First, you'll need Mono, which provides open-source implementations of .NET Framework APIs and includes the reference assemblies for versions like 4.0 and 4.5.2. Install it via Homebrew:

brew install mono

Once installed, Mono stores the reference assemblies in a path like /Library/Frameworks/Mono.framework/Versions/Current/lib/mono/4.5.2/ (adjust the version number to match your target, e.g., 4.0 for .NET Framework 4.0).

2. Configure Your myApp.csproj File #

Next, update your project file to target the desired .NET Framework version and point MSBuild to Mono's reference assemblies. Open myApp.csproj and modify the <PropertyGroup> section:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <!-- Target .NET Framework 4.5.2 -->
    <TargetFramework>net452</TargetFramework>
    <!-- Tell MSBuild to use Mono's reference assemblies -->
    <FrameworkPathOverride>/Library/Frameworks/Mono.framework/Versions/Current/lib/mono/4.5.2</FrameworkPathOverride>
  </PropertyGroup>

  <!-- Keep your existing package references, e.g., for RustFlakes -->
  <ItemGroup>
    <PackageReference Include="RustFlakes" Version="x.x.x" />
  </ItemGroup>
</Project>

If you need to support both .NET Core and .NET Framework, use <TargetFrameworks> (plural) instead:

<TargetFrameworks>netcoreapp2.1;net452</TargetFrameworks>

3. Verify the Setup #

• Run dotnet build to compile your project. If everything is configured correctly, it should build successfully targeting .NET Framework 4.5.2.
• To confirm the target framework, check the output directory (e.g., bin/Debug/net452/)—you'll see assemblies built for .NET Framework.
• Note that while you can compile on macOS, you'll need to use Mono to run the resulting executable:

  mono bin/Debug/net452/myApp.exe
  

Key Notes #

• .NET Framework isn't natively supported on macOS, so we're using Mono as a compatibility layer. Make sure any NuGet packages (like RustFlakes) are compatible with Mono and .NET Framework 4.5.2.
• If you run into issues with reference assemblies, double-check the FrameworkPathOverride path matches the version you're targeting in Mono.

内容的提问来源于stack exchange，提问作者kenorb