C# CompilationFailedException在运行时从AspNetCore TestHost编译Razor期间发生异常

我有ASP.NETMVC应用程序，其中一部分是将razor视图编译为字符串。代码与此示例非常相似：

我以以下方式在Startup.cs中注册了Razor引擎：

var viewAssembly = typeof(HtmlGeneratorService).GetTypeInfo().Assembly;
var fileProvider = new EmbeddedFileProvider(
    viewAssembly,
    "ApplicationServices.Widgets.Html.Templates");

services.Configure<MvcRazorRuntimeCompilationOptions>(options => {
    options.FileProviders.Clear();
    options.FileProviders.Add(fileProvider);
});

services.AddRazorPages().AddRazorRuntimeCompilation();

---

我尝试了很多不同的方法来修复这个错误，但是看起来我被困在这里了。

看起来我在这篇文章中找到了答案：

我刚刚将此代码添加到test.csproj文件中：

<Target Name="CopyDepsFiles" AfterTargets="Build" Condition="'$(TargetFramework)'!=''">
<ItemGroup>
  <DepsFilePaths Include="$([System.IO.Path]::ChangeExtension('%(_ResolvedProjectReferencePaths.FullPath)', '.deps.json'))" />
</ItemGroup>

<Copy SourceFiles="%(DepsFilePaths.FullPath)" DestinationFolder="$(OutputPath)" Condition="Exists('%(DepsFilePaths.FullPath)')" />

---

在项目中发布已安装的软件包可能会有所帮助。我怀疑您的一个或多个程序包可能未更新到3.1。我安装了Microsoft.AspNetCore.Razor，并更新了其余的程序包，但没有帮助。这会将assemblyname.deps.json从Razor程序集复制到宿主程序集的输出路径。Razor需要此文件进行运行时编译。

Microsoft.AspNetCore.Mvc.Razor.RuntimeCompilation.CompilationFailedException: 'One or more compilation failures occurred:
rnouw0xu.21w(4,41): error CS0234: The type or namespace name 'Razor' does not exist in the namespace 'Microsoft.AspNetCore' (are you missing an assembly reference?)
rnouw0xu.21w(4,82): error CS0518: Predefined type 'System.Type' is not defined or imported
rnouw0xu.21w(4,110): error CS0518: Predefined type 'System.String' is not defined or imported
rnouw0xu.21w(4,127): error CS0518: Predefined type 'System.String' is not defined or imported
rnouw0xu.21w(8,11): error CS0246: The type or namespace name 'System' could not be found (are you missing a using directive or an assembly reference?)
rnouw0xu.21w(9,11): error CS0246: The type or namespace name 'System' could not be found (are you missing a using directive or an assembly reference?)
rnouw0xu.21w(10,11): error CS0246: The type or namespace name 'System' could not be found (are you missing a using directive or an assembly reference?)
rnouw0xu.21w(11,11): error CS0246: The type or namespace name 'System' could not be found (are you missing a using directive or an assembly reference?)
rnouw0xu.21w(13,36): error CS0234: The type or namespace name 'Rendering' does not exist in the namespace 'Microsoft.AspNetCore.Mvc' (are you missing an assembly reference?)
rnouw0xu.21w(14,36): error CS0234: The type or namespace name 'ViewFeatures' does not exist in the namespace 'Microsoft.AspNetCore.Mvc' (are you missing an assembly reference?)
rnouw0xu.21w(29,35): error CS0234: The type or namespace name 'Razor' does not exist in the namespace 'Microsoft.AspNetCore' (are you missing an assembly reference?)
rnouw0xu.21w(29,78): error CS0518: Predefined type 'System.String' is not defined or imported
rnouw0xu.21w(29,87): error CS0518: Predefined type 'System.String' is not defined or imported

<Target Name="CopyDepsFiles" AfterTargets="Build" Condition="'$(TargetFramework)'!=''">
<ItemGroup>
  <DepsFilePaths Include="$([System.IO.Path]::ChangeExtension('%(_ResolvedProjectReferencePaths.FullPath)', '.deps.json'))" />
</ItemGroup>

<Copy SourceFiles="%(DepsFilePaths.FullPath)" DestinationFolder="$(OutputPath)" Condition="Exists('%(DepsFilePaths.FullPath)')" />