如何正确地将 OData 与 ASP.net Core 集成

Question

我正在尝试使用 OData 和 EntityFramework 创建一个带有“简单”Web API 的新 ASP.NET Core 项目。我以前在旧版本的 ASP.NET 中使用过 OData。

我已经设置了一个只有一个简单的 get 函数的控制器。我已经设法让它使用基本的 OData 命令作为过滤器和顶部，但我无法让扩展命令工作。我认为这是因为我不太清楚如何在 Startup.cs 中进行设置。我尝试了很多东西，包括关注 Github 的一些 odata 示例：

https://github.com/OData/WebApi/tree/vNext/vNext/samples/ODataSample.Web https://github.com/bigfont/WebApi/tree/master/vNext/samples/ODataSample.Web

在我的启动文件中，我尝试从服务类中排除一些根本没有效果的属性。所以问题可能出在我使用 IDataService 接口的方式上。 （ApplicationContext 像示例中一样实现它）

需要明确的是，我正在创建一个具有完整 .NET Framework 而不仅仅是 .Core 框架的 ASP.NET Core Web api。我当前的代码混合了两个示例的最佳/最差，并且在某种意义上可以过滤 WebAPI，但无法扩展或隐藏属性。

任何人都可以看到我缺少什么以及有一个有效的 ASP.NET Odata 示例。我对 startup.cs 中的整个设置不熟悉？我想我正在寻找能够完成这项工作的人。

控制器

[EnableQuery]
[Route("odata/Services")]
public class ServicesController : Controller
{
    private IGenericRepository<Service> _serviceRepo;
    private IUnitOfWork _unitOfWork;

    public ServicesController(IGenericRepository<Service> serviceRepo, IUnitOfWork unitOfWork)
    {
        _serviceRepo = serviceRepo;
        _unitOfWork = unitOfWork;
    }

    [HttpGet]
    public IQueryable<Service> Get()
    {
        var services = _serviceRepo.AsQueryable();
        return services;
    }
}

启动

using Core.DomainModel;
using Core.DomainServices;
using Infrastructure.DataAccess;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Configuration;
using Microsoft.AspNetCore.OData.Extensions;

namespace Web
{
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();

        if (env.IsDevelopment())
        {
            // This will push telemetry data through Application Insights pipeline faster, allowing you to view results immediately.
            builder.AddApplicationInsightsSettings(developerMode: true);
        }
        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)
    {
        // Add framework services.
        services.AddApplicationInsightsTelemetry(Configuration);
        services.AddMvc().AddWebApiConventions();

        services.AddSingleton<ApplicationContext>(_ => ApplicationContext.Create());

        services.AddSingleton<IDataService, ApplicationContext>();

        services.AddOData<IDataService>(builder =>
        {
            //builder.EnableLowerCamelCase();
            var service = builder.EntitySet<Service>("Services");
            service.EntityType.RemoveProperty(x => x.CategoryId);
            service.EntityType.RemoveProperty(x => x.PreRequisiteses);
        });


        services.AddSingleton<IGenericRepository<Service>, GenericRepository<Service>>();
        services.AddSingleton<IUnitOfWork, UnitOfWork>();
    }

    // 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();

        //ODataConventionModelBuilder builder = new ODataConventionModelBuilder();

        app.UseApplicationInsightsRequestTelemetry();

        //var builder = new ODataConventionModelBuilder(app.ApplicationServices.GetRequiredService<AssembliesResolver>());
        //var serviceCtrl = nameof(ServicesController).Replace("Controller", string.Empty);
        //var service = builder.EntitySet<Service>(serviceCtrl);
        //service.EntityType.RemoveProperty(x => x.CategoryId);

        app.UseOData("odata");

        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
            app.UseBrowserLink();
        }
        else
        {
            app.UseExceptionHandler("/Home/Error");
        }

        app.UseApplicationInsightsExceptionTelemetry();

        app.UseStaticFiles();

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

Project.json 依赖项

  "dependencies": {
    "Microsoft.ApplicationInsights.AspNetCore": "1.0.2",
    "Microsoft.AspNet.Identity.EntityFramework": "2.2.1",
    "Microsoft.AspNetCore.Diagnostics": "1.0.0",
    "Microsoft.AspNetCore.Identity": "1.0.0",
    "Microsoft.AspNetCore.Mvc": "1.0.1",
    "Microsoft.AspNetCore.Razor.Tools": {
      "version": "1.0.0-preview2-final",
      "type": "build"
    },
    "Microsoft.AspNetCore.Routing": "1.0.1",
    "Microsoft.AspNetCore.Server.IISIntegration": "1.0.0",
    "Microsoft.AspNetCore.Server.Kestrel": "1.0.1",
    "Microsoft.AspNetCore.StaticFiles": "1.0.0",
    "Microsoft.Extensions.Configuration.EnvironmentVariables": "1.0.0",
    "Microsoft.Extensions.Configuration.Json": "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.VisualStudio.Web.BrowserLink.Loader": "14.0.0",
    "Microsoft.AspNetCore.OData": "1.0.0-rtm-00015",
    "dnx-clr-win-x86": "1.0.0-rc1-update2",
    "Microsoft.OData.Core": "7.0.0",
    "Microsoft.OData.Edm": "7.0.0",
    "Microsoft.Spatial": "7.0.0"
}

Answer 1

从 WEB API 服务器端：

最简单的使用方法是直接 [EnableQuery] 属性。现在使用最近的 7.x 包，它运行良好。

你也可以很容易地拥有通用的实现，如下所示。想法是有一个通用的方法，并根据您需要的实体名称消除歧义。使用 Linq2RestANC 进行客户端消费，您也可以轻松传递自定义查询参数。如下例所示，如果您有 2 个表 Movies1 和 Movies2，那么当您在其中执行 $expand 和 sub-filter/sub-process 条件时，查询将仅直接应用于您的数据库。

[EnableQuery]
public IActionResult Get([FromQuery] string name)
{
        switch (name)
        {
            case "Movie2":
                return Ok(new List<ViewModel>{new ViewModel(Movies2=_db.Movies2)});
        }
        return Ok(new List<ViewModel>{new ViewModel(Movies1=_db.Movies1)});
 }

对于客户端消费- --> 不要使用 ODATA 服务代理。它是错误的并且会引发很多错误。 --> Simple.OData.Client 很好。但是对 expand 中的嵌套查询的支持滞后。 例如。 /Products?$expand=供应商($select=SupplierName;$top=1;) 对于这种内部扩展，它不支持进一步过滤。这被跟踪为错误 #200

--> Linq2RestANC 是一个不错的选择。那也原生不支持嵌套展开，但它是通过继承原生的IQueryProvider实现的，所以修改和测试完成的嵌套——深层次展开场景只需要3-4个小时。您需要在 Expressionprocessor.cs "Expand" 和 ParameterBuilder.cs GetFullUri() 处稍作更改以使其正常工作。

Answer 2

看起来这目前在 OData 团队中处于 alpha 阶段。 according to this issue

Answer 3

我也让Microsoft.AspNetCore.OData.vNext、version 6.0.2-alpha-rtm 工作，但我使用以下代码将Edm 模型映射到路由：

services.AddOData();
// ...
app.UseMvc(routes =>
{
  ODataModelBuilder modelBuilder = new ODataConventionModelBuilder();
  modelBuilder.EntitySet<Product>("Products");
  IEdmModel model = modelBuilder.GetEdmModel();
  routes.MapODataRoute(
    prefix: "odata",
      model: model
  );

还有services.AddOData()

这很奇怪，但它似乎适用于 .Net Core 1.1

Answer 4

我设法让它工作，但我没有使用提供的 OData 路由，因为我需要更多粒度。使用此解决方案，您可以创建自己的 Web API，同时仍允许使用 OData 查询参数。

注意事项：

• 我使用了Nuget包Microsoft.AspNetCore.OData.vNext，版本6.0.2-alpha-rtm，需要.NET 4.6.1
• 据我所知，OData vNext 仅支持 OData v4（所以不支持 v3）
• OData vNext 似乎很匆忙，并且充满了错误。例如，$orderby 查询参数已损坏

MyEntity.cs

namespace WebApplication1
{
    public class MyEntity
    {
        // you'll need a key 
        public int EntityID { get; set; }
        public string SomeText { get; set; }
    }
}

Startup.cs

using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.OData;
using Microsoft.AspNetCore.OData.Abstracts;
using Microsoft.AspNetCore.OData.Builder;
using Microsoft.AspNetCore.OData.Extensions;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using System;

namespace WebApplication1
{
    public class Startup
    {
        public Startup(IHostingEnvironment env)
        {
            var builder = new ConfigurationBuilder()
                .SetBasePath(env.ContentRootPath)
                .AddJsonFile("appsettings.json", optional: false, reloadOnChange: true)
                .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true)
                .AddEnvironmentVariables();
            Configuration = builder.Build();
        }

        public IConfigurationRoot Configuration { get; }

        public void ConfigureServices(IServiceCollection services)
        {
            services.AddMvc();

            /* ODATA part */
            services.AddOData();
            // the line below is used so that we the EdmModel is computed only once
            // we're not using the ODataOptions.ModelManager because it doesn't seemed plugged in
            services.AddSingleton<IODataModelManger, ODataModelManager>(DefineEdmModel);
        }

        private static ODataModelManager DefineEdmModel(IServiceProvider services)
        {
            var modelManager = new ODataModelManager();

            // you can add all the entities you need
            var builder = new ODataConventionModelBuilder();
            builder.EntitySet<MyEntity>(nameof(MyEntity));
            builder.EntityType<MyEntity>().HasKey(ai => ai.EntityID); // the call to HasKey is mandatory
            modelManager.AddModel(nameof(WebApplication1), builder.GetEdmModel());

            return modelManager;
        }

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

            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
                app.UseBrowserLink();
            }
            else
            {
                app.UseExceptionHandler("/Home/Error");
            }

            app.UseStaticFiles();

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

Controller.cs

using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.OData;
using Microsoft.AspNetCore.OData.Abstracts;
using Microsoft.AspNetCore.OData.Query;
using System.Linq;

namespace WebApplication1.Controllers
{
    [Produces("application/json")]
    [Route("api/Entity")]
    public class ApiController : Controller
    {
        // note how you can use whatever endpoint
        [HttpGet("all")]
        public IQueryable<MyEntity> Get()
        {
            // plug your entities source (database or whatever)
            var entities = new[] {
                new MyEntity{ EntityID = 1, SomeText = "Test 1" },
                new MyEntity{ EntityID = 2, SomeText = "Test 2" },
                new MyEntity{ EntityID = 3, SomeText = "Another texts" },
            }.AsQueryable();

            var modelManager = (IODataModelManger)HttpContext.RequestServices.GetService(typeof(IODataModelManger));
            var model = modelManager.GetModel(nameof(WebApplication1));
            var queryContext = new ODataQueryContext(model, typeof(MyEntity), null);
            var queryOptions = new ODataQueryOptions(queryContext, HttpContext.Request);

            return queryOptions
                .ApplyTo(entities, new ODataQuerySettings
                {
                    HandleNullPropagation = HandleNullPropagationOption.True
                })
                .Cast<MyEntity>();
        }
    }
}

如何测试

您可以使用以下 URI：/api/Entity/all?$filter=contains(SomeText,'Test')。如果它正常工作，您应该只会看到前两个实体。

Answer 5

我有一个 github 存储库，它使用 T4 从代码优先 EF 模型自动生成 ASP.NET Core OData v4 控制器。它使用 Microsoft.AspNetCore.OData.vNext 6.0.2-alpha-rtm。可能会感兴趣。

https://github.com/afgbeveridge/AutoODataEF.Core

Answer 6

你需要从 ODataController 继承控制器