求助：无法加载程序集Xamarin.Forms.Build.Tasks及依赖项问题

Hey Marco, sorry to hear you're stuck with this frustrating build error—those assembly loading issues can be total time-sinks when you've already tried the usual fixes. Let's dive into some less common but often effective steps to get your solution loading again:

• Manually verify and fix project file references
  Sometimes old .csproj files have hardcoded or broken paths to the build tasks DLL. Right-click your project → Edit Project File, then search for Xamarin.Forms.Build.Tasks. Check the HintPath attribute—it should point to the correct location in your NuGet packages folder, like:

  <HintPath>..\packages\Xamarin.Forms.{your-version}\build\Xamarin.Forms.Build.Tasks.dll</HintPath>
  

  If the path is wrong or the version number doesn't match your installed Xamarin.Forms package, update it, save the file, and reload the project.

• Clear your entire NuGet cache
  Deleting the local packages folder is good, but corrupted packages in your global NuGet cache can still cause issues. Try:

  • Using the command line: Run dotnet nuget locals all --clear in a terminal.
  • In Visual Studio: Go to Tools → NuGet Package Manager → Package Manager Settings → Clear All NuGet Cache(s).
    After clearing, right-click your solution → Restore NuGet Packages.

• Reinstall the Xamarin.Forms.Build.Tasks package explicitly
  Sometimes updating Xamarin.Forms doesn't properly refresh the build tasks. Open the Package Manager Console and run these commands (replace {your-project-version} with the exact Xamarin.Forms version your project uses):

  Uninstall-Package Xamarin.Forms.Build.Tasks -Force
  Install-Package Xamarin.Forms.Build.Tasks -Version {your-project-version}
  

  This ensures the build tasks package matches your main Xamarin.Forms version exactly.

• Check for GAC (Global Assembly Cache) conflicts
  Old versions of the build tasks might be stuck in the GAC, which can override your NuGet package references. Open an elevated Command Prompt and run:

  gacutil /u Xamarin.Forms.Build.Tasks
  

  If the command reports a successful uninstall, go back and restore your NuGet packages again.

• Compare with a fresh Xamarin.Forms project
  Create a new blank Xamarin.Forms project using the same version as your existing one. Open its .csproj file and compare how Xamarin.Forms.Build.Tasks is referenced. Copy the correct <Reference> or <UsingTask> blocks into your problematic project file—this can fix hidden configuration mismatches.

• Repair your Visual Studio installation
  If none of the above work, there might be a corrupted Xamarin component in your Visual Studio setup. Open the Visual Studio Installer, select your installed version, click Modify, then choose Repair for the Mobile development with .NET workload.

Hopefully one of these steps gets your solution loading smoothly again!

内容的提问来源于stack exchange，提问作者Marco Donzella