Xamarin.Forms安卓项目编译错误：Csc任务OutputAssembly参数异常

Hey there, sorry to hear you're stuck with this CSC task error after resolving the earlier IO exception in your cross-platform Xamarin.Forms project. Let's go through practical fixes to get past this issue:

• Clean and Rebuild Your Solution Thoroughly

  • First, right-click your solution in Visual Studio and select Clean Solution to clear existing build artifacts.
  • Navigate to your Android project's directory manually and delete the bin and obj folders—sometimes the IDE's clean command misses leftover files that cause conflicts.
  • Rebuild the solution, starting with your shared/PCL project first, then the Android project.

• Verify Android Project Output Settings

  • Right-click your Android project → Properties → Build → Output.
  • Double-check that the Output path field only contains a single valid directory, with no duplicate entries or extra semicolons.
  • Head to the Advanced build settings (under the same Build tab) and confirm the Output file name isn't configured to generate duplicate assembly files.

• Manually Fix the Project File (.csproj)

  • Close Visual Studio entirely, then locate your Android project's .csproj file and open it with a text editor (like Notepad++ or VS Code).
  • Search for <OutputAssembly> entries—you might find duplicate lines pointing to the same DLL path, like this:

    <OutputAssembly>obj\Debug\Test.Droid.dll</OutputAssembly>
    <OutputAssembly>obj\Debug\Test.Droid.dll</OutputAssembly>
    

  • Delete one of the duplicate lines, save the file, then reopen your solution in Visual Studio and rebuild.

• Check for Duplicate References or NuGet Conflicts

  • In your Android project's References section, make sure you don't have duplicate references to Test.Droid.dll or any related assemblies.
  • Open the NuGet Package Manager for your solution, check for any outdated or conflicting packages, and try updating them or reinstalling the Xamarin.Forms-related packages.

If none of these steps resolve the issue, you could also try resetting Visual Studio's component cache, or even creating a new blank Xamarin Android project and migrating your existing code/files over—occasionally project files can get corrupted in hard-to-spot ways that cause these odd build errors.

内容的提问来源于stack exchange，提问作者Deep Soni