迁移应用程序时无法加载类型 'Microsoft.Extensions.DependencyInjection.ServiceCollectionExtensions'

Question

我正在使用 VS Code 开发 .Net Core RTM web api。当我运行命令 dotnet ef migrations add "myfirstMigraion" 进行迁移时，出现如下图所示的错误。 :- 我的 project.json 文件看起来像：-

{
  "dependencies": {
    "Microsoft.NETCore.App": {
      "version": "1.0.0",
      "type": "platform"
    },
    "Microsoft.EntityFrameworkCore.Design": {
      "type": "build",
      "version": "1.0.0-preview2-final"
    },
    "Microsoft.AspNetCore.Mvc": "1.0.0",
    "Microsoft.AspNetCore.Server.IISIntegration": "1.0.0",
    "Microsoft.AspNetCore.Server.Kestrel": "1.0.0",
    "Microsoft.Extensions.DependencyInjection.Abstractions":"1.0.0",
    "Microsoft.Extensions.Configuration.EnvironmentVariables": "1.0.0",
    "Microsoft.Extensions.Configuration.FileExtensions": "1.0.0",
    "Microsoft.Extensions.Configuration.Json": "1.0.0",
    "Microsoft.Extensions.Configuration.CommandLine": "1.0.0",
    "Microsoft.Extensions.Logging": "1.0.0",
    "Microsoft.Extensions.Logging.Console": "1.0.0",
    "Microsoft.Extensions.Logging.Debug": "1.0.0",
    "Microsoft.Extensions.Options.ConfigurationExtensions": "1.0.0",
    "Microsoft.EntityFrameworkCore": "1.0.0-*",
    "Microsoft.EntityFrameworkCore.SqlServer": "1.0.0-rc2-final",
    "Microsoft.EntityFrameworkCore.InMemory": "1.0.0-rc2-final",
    // "Microsoft.EntityFrameworkCore.Tools":"1.0.0-preview2-final",
    "Microsoft.EntityFrameworkCore.SqlServer.Design": "1.0.0-rc2-final"
  },
  "tools": {
    "Microsoft.AspNetCore.Server.IISIntegration.Tools": "1.0.0-preview2-final",
    "Microsoft.EntityFrameworkCore.Tools": "1.0.0-preview2-final"
  },
  "frameworks": {
    "netcoreapp1.0": {
      "imports": [
        "dotnet5.6",
        "portable-net45+win8"
      ]
    }
  },
  "buildOptions": {
    "emitEntryPoint": true,
    "preserveCompilationContext": true,
    "debugType": "portable"
  },
  "runtimeOptions": {
    "configProperties": {
      "System.GC.Server": true
    }
  },
  "publishOptions": {
    "include": [
      "wwwroot",
      "Views",
      "Areas/**/Views",
      "appsettings.json",
      "web.config"
    ]
  },
  "scripts": {
    "postpublish": [
      "dotnet publish-iis --publish-folder %publish:OutputPath% --framework %publish:FullTargetFramework%"
    ]
  },
  "tooling": {
    "defaultNamespace": "firstCoreApi"
  }
}

看起来像我的 Startup.cs :-

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Infrastructure;
using firstCoreApi.Model;
namespace firstCoreApi
{
    public class Startup
    {
        public Startup(IHostingEnvironment env)
        {
            var builder = new ConfigurationBuilder()
                .SetBasePath(env.ContentRootPath)
                .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)
                .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)
                .AddEnvironmentVariables();
            Configuration = builder.Build();
        }

        public IConfigurationRoot Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            var connection = @"Server=myPcName\SQLEXPRESS; Database=StudentsDB;user id=MysqlUserId;password=Mysqlpassword;Trusted_Connection=True;MultipleActiveResultSets=true";
            //Server=SQLSERVERNAME;Database=StudentsDB;user id=sa;password=sa1;Trusted_Connection=True;MultipleActiveResultSets=true;
            // Add framework services.
            services.AddMvc();
            //  services.AddDbContext<TodoListDbContext>(options => options.UseInMemoryDatabase());
            services.AddDbContext<BloggingContext>(options => options.UseSqlServer(connection));
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
        {
            loggerFactory.AddConsole(Configuration.GetSection("Logging"));
            loggerFactory.AddDebug();

            app.UseMvc();
        }
    }
}

我正在使用操作系统 Windows 10 和 sql 服务器 2014。我需要你的帮助，伙计们如何修复它。

Answer 1

我也出现了同样的异常，我只是 "Microsoft.AspNetCore.Routing": "1.0.0-rc2-final" 更改为 "Microsoft.AspNetCore.Routing": "1.0.0"。它的工作

我认为如果您使用 VSCODE，您可以尝试在 project.json

中进行更改

"Microsoft.EntityFrameworkCore": "1.0.0",
"Microsoft.EntityFrameworkCore.SqlServer": "1.0.0",
"Microsoft.EntityFrameworkCore.InMemory": "1.0.0",
"Microsoft.EntityFrameworkCore.SqlServer.Design": "1.0.0"

Answer 2

我遇到了同样的问题。从命令行安装包。求助网站：https://www.nuget.org/packages/Kendo.Mvc/2016.2.630-Preview

在包管理器中使用的命令：Install-Package Kendo.Mvc -Pre

NuGet returns搜索到的包是最新的稳定包，里面有bug，哈哈！这就是为什么您需要从包管理器中的命令行安装的原因。

Telerik 知道这个问题：https://github.com/telerik/kendo-ui-core/issues/1856

迁移应用程序时无法加载类型 'Microsoft.Extensions.DependencyInjection.ServiceCollectionExtensions'

Could not load type 'Microsoft.Extensions.DependencyInjection.ServiceCollectionExtensions' while Migrating application

c#

asp.net-mvc

entity-framework

entity-framework-migrations

asp.net-web-api