visual-studio - 错误MSB4062 : The "Xamarin.Forms.Build.Tasks.GetTasksAbi" task could not be loaded from the assembly

Question

将软件包“Xamarin.Forms”和“Xamarin.Forms.Maps”更新到最新版本即“3.0.0.446417”后，该项目将不再生成，并且出现此错误:

    C:\Users\[MyUser]\.nuget\packages\xamarin.forms\3.0.0.446417\build\netstandard2.0\Xamarin.Forms.targets(35,3):
error MSB4062: The "Xamarin.Forms.Build.Tasks.GetTasksAbi" task could not be loaded from the assembly
C:\Users\[MyUser]\.nuget\packages\xamarin.forms\3.0.0.446417\build\netstandard2.0\Xamarin.Forms.Build.Tasks.dll.
Could not load file or assembly 'netstandard, Version=2.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51' or one of its dependencies.
The system cannot find the file specified. Confirm that the <UsingTask> declaration is correct, that the assembly and all its dependencies are available, and that the task contains a public class that implements Microsoft.Build.Framework.ITask.

该错误指向文件Xamarin.Forms.Targets的该位置:

<XamlGTask
    XamlFiles="@(EmbeddedResource)" Condition="'%(Extension)' == '.xaml' AND '$(DefaultLanguageSourceExtension)' == '.cs'"
    Language = "$(Language)"
    AssemblyName = "$(AssemblyName)"
    OutputPath = "$(IntermediateOutputPath)">
    <Output ItemName="FilesWrite" TaskParameter="GeneratedCodeFiles" />
    <Output ItemName="Compile" TaskParameter="GeneratedCodeFiles" />
</XamlGTask>

XamlGTask的下划线带有警告，指出:

Task 'XamlGTask' is not defined

到目前为止，我所做的是清理整个解决方案，删除obj/bin文件夹以及从“程序包管理器设置”中清除“所有Nuget缓存”，但它们都无济于事。

Answer 1

error MSB4062: The “Xamarin.Forms.Build.Tasks.GetTasksAbi” task could not be loaded from the assembly

要解决此问题，您绝对应该确保所有项目都引用相同版本的软件包Xamarin.Forms 。

在您的Solution Explorer中，右键单击您的解决方案节点，然后选择Manage NuGet Packages for solution...。选择Consolidate选项卡，然后单击Xamarin.Forms NuGet包，确认所有项目使用相同版本。如果不是，请全部更新为相同版本。

此外，有人说安装.NET Framework 4.7.1将有助于解决此问题，您可以检查是否有帮助。

认证:https://forums.xamarin.com/discussion/comment/324869#Comment_324869

注意:如果无法成功安装.net Framework 4.7.1，请尝试将Windows 10更新到最新版本。谢谢@Vahid。

希望这可以帮助。