问题描述:在ASP.NET Core 3.1中使用OData时,无法通过Id选择实体。
解决方法: 要通过Id选择实体,需要在OData配置中添加一个路由。以下是解决方法的代码示例:
首先,确保已经安装了以下NuGet包:
在Startup.cs文件中,添加以下代码:
using Microsoft.AspNet.OData.Extensions;
public void ConfigureServices(IServiceCollection services)
{
services.AddControllers(mvcOptions =>
{
// 添加OData路由
mvcOptions.EnableEndpointRouting = false;
mvcOptions.Select().Expand().Filter().OrderBy().MaxTop(100).Count();
mvcOptions.MapODataServiceRoute("odata", "odata", GetEdmModel());
});
// 注册OData服务
services.AddOData();
}
private static IEdmModel GetEdmModel()
{
var builder = new ODataConventionModelBuilder();
builder.EntitySet("Entities");
return builder.GetEdmModel();
}
using Microsoft.AspNet.OData;
using Microsoft.AspNet.OData.Query;
using Microsoft.AspNetCore.Mvc;
[Route("odata/[controller]")]
[ApiController]
public class EntitiesController : ControllerBase
{
private readonly List _entities = new List
{
new Entity { Id = 1, Name = "Entity 1" },
new Entity { Id = 2, Name = "Entity 2" },
new Entity { Id = 3, Name = "Entity 3" }
};
[HttpGet]
[EnableQuery]
public IActionResult Get(ODataQueryOptions queryOptions)
{
return Ok(_entities.AsQueryable());
}
[HttpGet("{id}")]
[EnableQuery]
public IActionResult Get(int id, ODataQueryOptions queryOptions)
{
var entity = _entities.FirstOrDefault(e => e.Id == id);
if (entity == null)
{
return NotFound();
}
return Ok(entity);
}
}
public class Entity
{
public int Id { get; set; }
public string Name { get; set; }
}
现在,你应该能够通过Id选择实体了。例如,通过以下请求获取Id为1的实体: GET /odata/Entities/1
请注意,这只是一个简单的示例,你可以根据自己的需求进行修改和扩展。