c# - 得到错误 Assets 文件 'obj\project.assets.json' 没有 '.NETCoreApp,Version=v2.2' 的目标

Question

我将我的 MVC 核心项目从 2.2 升级到 3.0 microsoft

这里推荐改很多:https://stackoverflow.com/

在本地运行时它工作正常，但是当我想在本地文件夹中发布时出现此错误:

Assets file 'obj\project.assets.json' doesn't have a target for '.NETCoreApp,Version=v2.2'. Ensure that restore has run and that you have included 'netcoreapp2.2' in the TargetFrameworks for your project

我有 3 个项目，所有项目都升级到 MVC 核心 3.0，还将所有包升级到 3.0也去掉object文件夹和bin文件夹，重新build工程，关闭VS再打开，还是报错。

更新: mvc 项目 csproj

<Project Sdk="Microsoft.NET.Sdk.Web">

<PropertyGroup>
  <TargetFramework>netcoreapp3.0</TargetFramework>   
</PropertyGroup>

<ItemGroup>
 <!--<PackageReference Include="Microsoft.AspNetCore.App" />-->
  <PackageReference Include="Microsoft.AspNetCore.Identity.UI" Version="3.0" 
 />      
   <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" 
Version="3.0.0" />
</ItemGroup>

<ItemGroup>
  <Folder Include="Areas\Admin\Data\" />
  <Folder Include="Areas\Admin\Models\" />
 </ItemGroup>

<ItemGroup>
  <ProjectReference Include="..\project.Model\project.Model.csproj" />
  <ProjectReference Include="..\project.Repo\project.Repo.csproj" />
</ItemGroup>

</Project>

我的项目.Model.csproj

<Project Sdk="Microsoft.NET.Sdk">

<PropertyGroup>
  <TargetFramework>netcoreapp3.0</TargetFramework>  
</PropertyGroup>

<ItemGroup>
  <PackageReference 
Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="3.0.0" />
<PackageReference Include="Microsoft.AspNetCore.Identity.UI" Version="3.0.0" />
<PackageReference Include="Microsoft.EntityFrameworkCore.Design" 
 Version="3.0.0">
  <PrivateAssets>all</PrivateAssets>
  <IncludeAssets>runtime; build; native; contentfiles; analyzers; 
   buildtransitive</IncludeAssets>
  </PackageReference>
  <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" 
 Version="3.0.0" />
<PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer.Design" 
 Version="1.1.6" />
<PackageReference Include="Microsoft.EntityFrameworkCore.Tools" 
 Version="3.0.0">
  <PrivateAssets>all</PrivateAssets>
  <IncludeAssets>runtime; build; native; contentfiles; analyzers; 
 buildtransitive</IncludeAssets>
 </PackageReference>
 </ItemGroup>

 </Project>

Answer 1

在我们的例子中，在从 netcoreapp30 切换到 netcoreapp31 作为目标框架之后，我们在发布时遇到了一个非常相似的错误。我们通过以下方式解决了它:

1. 关闭 Visual Studio
2. 删除文件\obj\project.assets.json
3. 再次打开解决方案
4. 重建解决方案

在那之后我们就可以很好地发布项目了。