Visual Studio中Xamarin组件安装失败，报错XA5209与XA5207

Hey there, I’ve run into this exact frustrating issue before when working with Xamarin.Forms and Xamarin.Android in Visual Studio—when the Android components refuse to auto-install, leaving you with empty zip packages and component folders. Let’s walk through the full, tested fix steps that resolved it for me, building on what you’ve already attempted.

Step 1: Fully Clean Xamarin & NuGet Caches #

You tried deleting the ./AppData/Local/Xamarin folder, but let’s cover all cache locations to ensure a fresh start:

• First, close Visual Studio entirely—double-check Task Manager to kill any lingering devenv.exe processes, as they might lock cache files.
• Delete these folders:
  • %LOCALAPPDATA%\Xamarin
  • %LOCALAPPDATA%\Xamarin.Android
  • %USERPROFILE%\AppData\Roaming\Xamarin
• Clear the NuGet cache by running this command in Command Prompt:

  nuget locals all -clear
  

Step 2: Complete the Manual m2repository Setup #

Your plan to use m2repository_r29 is spot-on—here’s how to finish it correctly:

1. Download the official m2repository_r29.zip (ensure it matches the target Android framework version your project uses).
2. Calculate the SHA-1 hash of the zip file:
   • Open Command Prompt, navigate to the folder containing the zip, then run:

     certutil -hashfile m2repository_r29.zip SHA1
     

   • Copy the resulting 40-character hash (remove any spaces from the output).
3. Rename the m2repository_r29.zip file to this hash value (don’t keep the .zip extension).
4. Move the renamed file to %LOCALAPPDATA%\Xamarin\zips—create the zips folder if it doesn’t exist.
5. Create a folder with the same hash name in the empty component directory (e.g., %LOCALAPPDATA%\Xamarin\Android.Support.v4 if that’s the missing component).
6. Extract all contents of m2repository_r29.zip into this new folder.

Step 3: Force Visual Studio to Restore Components #

• Open your solution in Visual Studio.
• Right-click your Android project > Manage NuGet Packages.
• Navigate to the Installed tab, find the problematic Android components (like Support libraries), uninstall them, then reinstall them.
• Alternatively, right-click the solution > Restore NuGet Packages to trigger a full restore.

Step 4: Verify Visual Studio & SDK Settings #

• Go to Tools > Options > Xamarin > Android Settings.
• Confirm the Android SDK Location points to your valid Android SDK folder (if not, browse to select it).
• Ensure the Automatically install missing packages when building option is checked.
• If you’re on a network with a proxy, add your proxy details here—proxy restrictions are a common culprit for failed component downloads.

Bonus: Update Visual Studio & Xamarin Tools #

Outdated versions of Visual Studio or Xamarin workloads often cause these download glitches. Head to Help > Check for Updates and install any available updates for Visual Studio and the Xamarin tools package.

内容的提问来源于stack exchange，提问作者Bob Parker