asp.net-core - ASP.NET 核心 3.1 :Adding Classes Libraries to the Project_ MissingMethodException: Method not found: 'Boolean Microsoft. EntityFrameworkCore.Migrations

Question

我正在处理 asp.net-core 3.1 项目，我为我的项目添加了 3 个类库来分离访问数据、模型类和实用程序类我解决了匹配文件夹等问题。但是当我运行我的项目时，我得到了这个错误:

MissingMethodException: Method not found: 'Boolean Microsoft.EntityFrameworkCore.Migrations.IMigrationsModelDiffer.HasDifferences(Microsoft.EntityFrameworkCore.Metadata.IModel, Microsoft.EntityFrameworkCore.Metadata.IModel)'.


   Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore.DatabaseErrorPageMiddleware.Invoke(HttpContext 
   httpContext)
   System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start<TStateMachine>(ref TStateMachine 
   stateMachine)
   System.Runtime.CompilerServices.AsyncTaskMethodBuilder.Start<TStateMachine>(ref TStateMachine 
   stateMachine)
   Microsoft.AspNetCore.Diagnostics.EntityFrameworkCore.DatabaseErrorPageMiddleware.Invoke(HttpContext 
   httpContext)
   Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)  

Answer 1

对我来说，答案是确保我所有的 EF 包都指向同一个 3.1.X 版本。我无意中瞄准了一个包含缺失方法的 5.0.0 EF 包:

https://learn.microsoft.com/en-us/dotnet/api/microsoft.entityframeworkcore.migrations.imigrationsmodeldiffer.hasdifferences?view=efcore-5.0