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c# – ASP.NET 5 EntityFramework.Core 7.0.0-rc1-final问题 –

发布时间:2020-12-15 06:41:38 所属栏目:百科 来源:网络整理
导读:我有同样的问题.我在project.json文件中添加了以下依赖项: "dependencies": { "EntityFramework": "7.0.0-beta4","EntityFramework.Core": "7.0.0-rc1-final","EntityFramework.SqlServer": "7.0.0-beta8","EntityFramework.Commands": "7.0.0-rc1-final" }
我有同样的问题.我在project.json文件中添加了以下依赖项:
"dependencies": {
    "EntityFramework": "7.0.0-beta4","EntityFramework.Core": "7.0.0-rc1-final","EntityFramework.SqlServer": "7.0.0-beta8","EntityFramework.Commands": "7.0.0-rc1-final"
  },"commands": {
    "web": "Microsoft.AspNet.Server.Kestrel","ef": "EntityFramework.Commands"
  },...

我用dnu安装EntityFramework和dnu安装EntityFramework.SqlServer来安装软件包. “EntityFramework”:“7.0.0-beta4”,由安装程序本身自动编写在依赖节点下.

问题1:令人惊讶的是,当我提到EntityFramework的智能化时,我提供的可用版本只有6.1.3!

问题2:当我使用dnu build编译我的应用程序(我在依赖项节点下手动添加EntityFramework程序集(.Core和.Commands)后运行dnu restore命令,我收到一堆编译错误:

The type 'DbContextOptionsBuilder' is defined in an assembly that is not referenced. You must add a reference to assembly 'EntityFramework.Core,Version=7.0.0.0,Culture=neutral,PublicKeyToken=null'.
D:ProjectsaspnetapiserviceModelsSampleData.cs(12,41): DNXCore,Version=v5.0 error CS0308: The non-generic method 'IServiceProvider.GetService(Type)' cannot be used with type arguments
D:ProjectsaspnetapiserviceModelsSampleData.cs(13,32): DNXCore,Version=v5.0 error CS0308: The non-generic method 'IServiceProvider.GetService(Type)' cannot be used with type arguments
D:ProjectsaspnetapiserviceModelsSampleData.cs(14,29): DNXCore,Version=v5.0 error CS1061: 'object' does not contain a definition for 'Books' and no extension method 'Books' accepting a first argument of type 'object' could be found (are you missing a using directive or an assembly reference?)
D:ProjectsaspnetapiserviceModelsSampleData.cs(15,42): DNXCore,Version=v5.0 error CS1061: 'object' does not contain a definition for 'Authors' and no extension method 'Authors' accepting a first argument of type 'object' could be found (are you missing a using directive or an assembly reference?)
D:ProjectsaspnetapiserviceModelsSampleData.cs(17,43): DNXCore,Version=v5.0 error CS1061: 'object' does not contain a definition for 'Authors' and no extension method 'Authors' accepting a first argument of type 'object' could be found (are you missing a using directive or an assembly reference?)
D:ProjectsaspnetapiserviceModelsSampleData.cs(19,45): DNXCore,Version=v5.0 error CS1061: 'object' does not contain a definition for 'Authors' and no extension method 'Authors' accepting a first argument of type 'object' could be found (are you missing a using directive or an assembly reference?)
D:ProjectsaspnetapiserviceModelsSampleData.cs(22,Version=v5.0 error CS1061: 'object' does not contain a definition for 'Books' and no extension method 'Books' accepting a first argument of type 'object' could be found (are you missing a using directive or an assembly reference?)
D:ProjectsaspnetapiserviceModelsSampleData.cs(61,Version=v5.0 error CS1061: 'object' does not contain a definition for 'SaveChanges' and no extension method 'SaveChanges' accepting a first argument of type 'object' could be found (are you missing a using directive or an assembly reference?)

如果我删除.Core和.Commands程序集引用项目构建正常.

然后我将EntityFramework.Core的版本更改为7.0.0.0,如错误所述:

The type 'DbContextOptionsBuilder' is defined in an assembly that is not referenced. You must add a reference to assembly 'EntityFramework.Core,PublicKeyToken=null'.

但是dnu恢复现在给了我以下内容:

Unable to locate Dependency EntityFramework.Core >= 7.0.0
Writing lock file D:Projectsaspnetapiserviceproject.lock.json
Restore complete,6675ms elapsed

Errors in D:Projectsaspnetapiserviceproject.json
    Unable to locate Dependency EntityFramework.Core >= 7.0.0

我是一个新手在asp.net 5 Visual Studio代码平台.我不能使用Visual Studio 2015作为开发团队的其他成员使用OSX.

这是一个为我学习的项目.要求很简单.连接SQL Server数据库,使用实体框架来拉大师级关系数据.

搞砸了!帮帮我!!

提前致谢

UPDATE

>我可以看到project.json对于版本7.0.0-rc1-final的所有软件包的重大变化.我使用Yeoman生成器工具来创建项目,但是看起来像是通过Visual Studio更正了包.那么,我必须手动更新软件包版本并恢复它们吗?
>当项目由Yeoman创建/生成时,默认情况下没有添加global.json文件.我可以手动添加这个代码吗?这会工作吗
>我还可以看到一些额外的包引用被添加到project.json文件,默认情况下没有被Yeoman生成器添加 – 如Microsoft.AspNet.Tooling.Razor,Microsoft.Extensions.Logging.Console,Microsoft.Extensions.Logging.Debug,Microsoft.Extensions.Logging等.这些项目是否都被有效地使用?因为生成器没有自动添加它们,可以再次手动添加它们,并使用dnu还原进行还原?如果我们手动添加,这会对项目有任何影响吗?

解决方法

您应该从依赖关系中删除“EntityFramework”(删除“EntityFramework”:“7.0.0-beta4”)并使用
"EntityFramework.MicrosoftSqlServer": "7.0.0-rc1-final","EntityFramework.MicrosoftSqlServer.Design": "7.0.0-rc1-final","EntityFramework.Commands": "7.0.0-rc1-final"

只要.如果添加“EntityFramework.MicrosoftSqlServer”:“7.0.0-rc1-final”,因为以下依赖关系,您不需要添加“EntityFramework.Core”:“7.0.0-rc1-final”:“7.0.0-rc1-final”

"EntityFramework.MicrosoftSqlServer": "7.0.0-rc1-final":
    "EntityFramework.Relational": "7.0.0-rc1-final":
        "EntityFramework.Core": "7.0.0-rc1-final"

我的意思是EntityFramework.MicrosoftSqlServer需要EntityFramework.Relational,这需要EntityFramework.Core.

您应该另外验证global.json包含“sdk”:{“version”:“1.0.0-rc1-update1”}.

UPDATED:我检查了你上传的测试项目.它有很多小问题.我修改了您可以下载修改的项目here.不要忘记修复在appsettings.json中使用的ConnectionString,它包含我在我使用的服务器.

最重要的更改是使用更简单的BookContext.cs:

using Microsoft.Data.Entity;

namespace apiservice.Models {
    public class BookContext : DbContext {
        public DbSet<Author> Authors { get; set; }
        public DbSet<Book> Books { get; set; }
    }
}

使用以下SampleData.cs

using System;
using System.Linq;
using Microsoft.Data.Entity;
using Microsoft.Extensions.DependencyInjection;

namespace apiservice.Models
{
    public static class SampleData
    {
        public static void Initialize(IServiceProvider serviceProvider) {
            var context=serviceProvider.GetService<BookContext>();
            context.Database.Migrate();
            if (!context.Books.Any()) {
                var austen = context.Authors.Add(
                    new Author { LastName = "Austen",FirstName = "Jane" }).Entity;
                var dickens = context.Authors.Add(
                    new Author { LastName = "Dickens",FirstName = "Charles" }).Entity;
                var cervantes = context.Authors.Add(
                    new Author { LastName = "Cervantes",FirstName = "Miguel" }).Entity;

                context.Books.AddRange(
                    new Book {
                        Title = "Pride and Prejudice",Year = 1813,Author = austen,Price = 9.99M,Genre = "Comedy of manners"
                    },new Book {
                        Title = "Northanger Abbey",Year = 1817,Price = 12.95M,Genre = "Gothic parody"
                    },new Book {
                        Title = "David Copperfield",Year = 1850,Author = dickens,Price = 15,Genre = "Bildungsroman"
                    },new Book {
                        Title = "Don Quixote",Year = 1617,Author = cervantes,Price = 8.95M,Genre = "Picaresque"
                    }
                );

                context.SaveChanges(); 
            }
        }
    }    
}

具有以下依赖项的project.json的用法部分:

{
  "dependencies": {
    "Microsoft.AspNet.Diagnostics": "1.0.0-rc1-final","Microsoft.AspNet.IISPlatformHandler": "1.0.0-rc1-final","Microsoft.AspNet.Mvc": "6.0.0-rc1-final","Microsoft.AspNet.Mvc.TagHelpers": "6.0.0-rc1-final","Microsoft.AspNet.Server.Kestrel": "1.0.0-rc1-final","Microsoft.AspNet.StaticFiles": "1.0.0-rc1-final","Microsoft.AspNet.Tooling.Razor": "1.0.0-rc1-final","Microsoft.Extensions.Configuration.FileProviderExtensions": "1.0.0-rc1-final","Microsoft.Extensions.Configuration.Json": "1.0.0-rc1-final","Microsoft.Extensions.Logging": "1.0.0-rc1-final","Microsoft.Extensions.Logging.Console": "1.0.0-rc1-final","Microsoft.Extensions.Logging.Debug": "1.0.0-rc1-final","Microsoft.Extensions.DependencyInjection": "1.0.0-rc1-final","Microsoft.Extensions.CodeGenerators.Mvc": "1.0.0-rc1-final","Microsoft.VisualStudio.Web.BrowserLink.Loader": "14.0.0-rc1-final","EntityFramework.MicrosoftSqlServer": "7.0.0-rc1-final","EntityFramework.Commands": "7.0.0-rc1-final","System.Net.Http": "4.0.1-beta-23516","Microsoft.Net.Http": "2.2.29","Newtonsoft.Json": "8.0.1"
  },"frameworks": {
    "dnx451": { },"dnxcore50": { }
  }
}

固定appsettings.json从

{
  "Logging": {
    "IncludeScopes": false,"LogLevel": {
      "Default": "Verbose","System": "Information","Microsoft": "Information"
    },"Data": {
        "DefaultConnection":{
            "ConnectionString": "Server=localhost;Database=BookStore;User Id=sa; Password=******;Trusted_Connection=true;"
        }
    }
  }
}

{
  "Logging": {
    "IncludeScopes": false,"Microsoft": "Information"
    }
  },"Data": {
    "DefaultConnection": {
      "ConnectionString": "Server=localhost;Database=BookStore;User Id=sa; Password=******;Trusted_Connection=true;"
    }
  }
}

(数据不应该在日志记录下)

并使用以下Startup.cs

using apiservice.Models;
using Microsoft.AspNet.Builder;
using Microsoft.AspNet.Hosting;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.Data.Entity;


namespace apiservice
{
    public class Startup
    {
        public static IConfigurationRoot Configuration {get; set;}

        public Startup(IHostingEnvironment env)
        {
            // Set up configuration sources.
            var builder = new ConfigurationBuilder()
                .AddJsonFile("appsettings.json")
                .AddJsonFile($"appsettings.{env.EnvironmentName}.json",optional: true)
                .AddEnvironmentVariables();
            Configuration = builder.Build();
        }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            // Add framework services.
            services.AddEntityFramework()
                .AddSqlServer()
                .AddDbContext<BookContext>(options => 
                    options.UseSqlServer(Configuration["Data:DefaultConnection:ConnectionString"])
                );

            services.AddMvc();
        }

        public void Configure(IApplicationBuilder app,ILoggerFactory loggerFactory)
        {
            loggerFactory.AddConsole(Configuration.GetSection("Logging"));
            loggerFactory.AddDebug();

            // we need to execute the following two commands before

            //    dnu restore
            //    dnx ef migrations add Initial
            //    dnx ef database update   

            // For more details on creating database during deployment see http://go.microsoft.com/fwlink/?LinkID=615859
            try
            {
                using (var serviceScope = app.ApplicationServices.GetRequiredService<IServiceScopeFactory>()
                    .CreateScope())
                {
                    serviceScope.ServiceProvider.GetService<BookContext>()
                         .Database.Migrate();
                }
            }
            catch { }

            app.UseIISPlatformHandler();

            app.UseStaticFiles();

            app.UseMvc(routes =>
            {
                routes.MapRoute(
                    name: "default",template: "{controller=Home}/{action=Index}/{id?}");
            });

            SampleData.Initialize(app.ApplicationServices);
        }

        // Entry point for the application.
        public static void Main(string[] args) => WebApplication.Run<Startup>(args);
    }
}

我在配置方法中的注释中写道,应该执行命令

dnx ef migrations add Initial
dnx ef database update

所有包恢复后. dnx ef migrations add Initial将在项目中创建其他Migrations文件夹,其中包含像20160101205609_Initial.cs和BookContextModelSnapshot.cs这样的文件.在appsettings.json中定义的数据库将由dnx ef数据库更新创建,并且在使用该程序进行分组时将从SampleData.cs填充测试数据.

顺便说一句,我将package.json移动到包文件夹(与project.json相同的级别)内.您使用的包不是,但运动使得npm包可见和管理在Visual Studio中.

(编辑:李大同)

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