如何添加 IDesignTimeDbContextFactory 的实现以添加迁移到 .Net core 2.0 应用程序？

我正在尝试从 .NET Core 2.0 MVC 应用程序的包管理器控制台运行 Add-Migration InitialCreate 命令。查看所有可能的来源后仍然无法解决问题，错误描述为：

PM> Add-Migration InitialCreate

在“Program”类上调用方法“BuildWebHost”时发生错误。在没有应用程序服务提供商的情况下继续。错误：找不到方法：'System.Collections.Generic.Dictionary2<System.String,System.Object> Microsoft.Extensions.Configuration.IConfigurationBuilder.get_Properties()'. System.IO.FileLoadException: Could not load file or assembly 'System.Diagnostics.DiagnosticSource, Version=4.0.2.1, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040) File name: 'System.Diagnostics.DiagnosticSource, Version=4.0.2.1, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51' at Microsoft.EntityFrameworkCore.Infrastructure.EntityFrameworkServicesBuilder.TryAddCoreServices() at Microsoft.Extensions.DependencyInjection.SqlServerServiceCollectionExtensions.AddEntityFrameworkSqlServer(IServiceCollection serviceCollection) at Microsoft.EntityFrameworkCore.Infrastructure.Internal.SqlServerOptionsExtension.ApplyServices(IServiceCollection services) at Microsoft.EntityFrameworkCore.Internal.ServiceProviderCache.ApplyServices(IDbContextOptions options, ServiceCollection services) at Microsoft.EntityFrameworkCore.Internal.ServiceProviderCache.<>c__DisplayClass4_0.<GetOrAdd>b__2(Int64 k) at System.Collections.Concurrent.ConcurrentDictionary2.GetOrAdd(TKey 键, Func2 valueFactory) at Microsoft.EntityFrameworkCore.DbContext..ctor(DbContextOptions options) at MvcMovie.Models.MvcMovieContext..ctor(DbContextOptions1 个选项）位于 C:\Users\Neha\source\repos\MvcMovie\MvcMovie\Data\MvcMovieContext.cs：第 12 行 在 C:\Users\Neha\source\repos\MvcMovie\MvcMovie\ToDoContextFactory.cs 中的 MvcMovie.ToDoContextFactory.CreateDbContext(String[] args)：第 17 行 在 Microsoft.EntityFrameworkCore.Design.Internal.DbContextOperations.CreateContext(Func1 factory) at Microsoft.EntityFrameworkCore.Design.Internal.DbContextOperations.CreateContext(String contextType) at Microsoft.EntityFrameworkCore.Design.Internal.MigrationsOperations.AddMigration(String name, String outputDir, String contextType) at Microsoft.EntityFrameworkCore.Design.OperationExecutor.AddMigrationImpl(String name, String outputDir, String contextType) at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.<>c__DisplayClass3_01.b__0() 在 Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute（操作操作）

Could not load file or assembly 'System.Diagnostics.DiagnosticSource, Version=4.0.2.1, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51'. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

我的 Program.cs 看起来像：

 public class Program
{
    public static void Main(string[] args)
    {
        var host = new WebHostBuilder()
            .UseKestrel()
            .UseContentRoot(Directory.GetCurrentDirectory())
            .UseIISIntegration()
            .UseStartup<Startup>()
            .UseApplicationInsights()
            .Build();

        host.Run();
    }

    public static IWebHost BuildWebHost(string[] args) =>
        new WebHostBuilder()
        .UseKestrel()
        .UseContentRoot(Directory.GetCurrentDirectory())
        .UseIISIntegration()
        .UseStartup<Startup>()
        .Build();
}

还添加了实现

IDesignTimeDbContextFactory

public class ToDoContextFactory : IDesignTimeDbContextFactory<MvcMovieContext>
{
    public MvcMovieContext CreateDbContext(string[] args)
    {
        var builder = new DbContextOptionsBuilder<MvcMovieContext>();
        builder.UseSqlServer("Server=(local);Database=MvcMovieContext;Trusted_Connection=True;MultipleActiveResultSets=true");
        return new MvcMovieContext(builder.Options);
    }
}

有人可以帮助我完成描述性的分步过程，将模型和实体框架工具添加到 .NET Core2.0 应用程序中。

您需要更改您的班级计划

public class Program
{
    public static void Main(string[] args)
    {
        BuildWebHost(args).Run();
    }

    public static IWebHost BuildWebHost(string[] args) =>
        WebHost.CreateDefaultBuilder(args)
            .UseStartup<Startup>()
            .Build();
}

这个班changed使用 dotnet 核心 2.0.0