Asp.net web api OData是否支持枚举类型的groupby？

OData的版本：

<?xml version="1.0" encoding="utf-8"?>
<packages>
  <package id="Microsoft.AspNet.OData" version="5.9.1" targetFramework="net45" />
  <package id="Microsoft.OData.Core" version="6.15.0" targetFramework="net45" />
  <package id="Microsoft.OData.Edm" version="6.15.0" targetFramework="net45" />
  <package id="Microsoft.Spatial" version="6.15.0" targetFramework="net45" />
</packages>

public enum Color
{
    Red = 1,
    Green = 2,
    Blue = 3
}

public class Vehicle
{
    public Guid VehicleId { get; set; }
    [JsonConverter(typeof(StringEnumConverter))]
    public Color? Color { get; set; }
}

[HttpGet]
[Route("vehicles")]
public IHttpActionResult GetVehicles(ODataQueryOptions<Vehicle> options)
{
    var query = dbContext.Vehicle.Select(x => new Vehicle
        {
            VehicleId = x.VehicleId,    // guid type for x.VehicleId
            Color = (Color?)x.ColorId    // nullable int type for x.ColorId
        });

    var odataQuery = options.ApplyTo(query) as IQueryable<object>;

    return Ok(odataQuery.AsEnumerable<Vehicle>());
}

车辆类别：

<?xml version="1.0" encoding="utf-8"?>
<packages>
  <package id="Microsoft.AspNet.OData" version="5.9.1" targetFramework="net45" />
  <package id="Microsoft.OData.Core" version="6.15.0" targetFramework="net45" />
  <package id="Microsoft.OData.Edm" version="6.15.0" targetFramework="net45" />
  <package id="Microsoft.Spatial" version="6.15.0" targetFramework="net45" />
</packages>

public enum Color
{
    Red = 1,
    Green = 2,
    Blue = 3
}

public class Vehicle
{
    public Guid VehicleId { get; set; }
    [JsonConverter(typeof(StringEnumConverter))]
    public Color? Color { get; set; }
}

[HttpGet]
[Route("vehicles")]
public IHttpActionResult GetVehicles(ODataQueryOptions<Vehicle> options)
{
    var query = dbContext.Vehicle.Select(x => new Vehicle
        {
            VehicleId = x.VehicleId,    // guid type for x.VehicleId
            Color = (Color?)x.ColorId    // nullable int type for x.ColorId
        });

    var odataQuery = options.ApplyTo(query) as IQueryable<object>;

    return Ok(odataQuery.AsEnumerable<Vehicle>());
}

Web API端点：

<?xml version="1.0" encoding="utf-8"?>
<packages>
  <package id="Microsoft.AspNet.OData" version="5.9.1" targetFramework="net45" />
  <package id="Microsoft.OData.Core" version="6.15.0" targetFramework="net45" />
  <package id="Microsoft.OData.Edm" version="6.15.0" targetFramework="net45" />
  <package id="Microsoft.Spatial" version="6.15.0" targetFramework="net45" />
</packages>

public enum Color
{
    Red = 1,
    Green = 2,
    Blue = 3
}

public class Vehicle
{
    public Guid VehicleId { get; set; }
    [JsonConverter(typeof(StringEnumConverter))]
    public Color? Color { get; set; }
}

[HttpGet]
[Route("vehicles")]
public IHttpActionResult GetVehicles(ODataQueryOptions<Vehicle> options)
{
    var query = dbContext.Vehicle.Select(x => new Vehicle
        {
            VehicleId = x.VehicleId,    // guid type for x.VehicleId
            Color = (Color?)x.ColorId    // nullable int type for x.ColorId
        });

    var odataQuery = options.ApplyTo(query) as IQueryable<object>;

    return Ok(odataQuery.AsEnumerable<Vehicle>());
}

[HttpGet]
[路线（“车辆”）]
公共IHttpActionResult获取车辆（ODataQueryOptions选项）
{
var query=dbContext.Vehicle.Select（x=>newvehicle
{
VehicleId=x.VehicleId，//x.VehicleId的guid类型
Color=（Color？）x.ColorId//x.ColorId的可空int类型
});
var odataQuery=options.ApplyTo（查询）为可查询的；
返回Ok（odataQuery.AsEnumerable（））；
}

场景1:

<?xml version="1.0" encoding="utf-8"?>
<packages>
  <package id="Microsoft.AspNet.OData" version="5.9.1" targetFramework="net45" />
  <package id="Microsoft.OData.Core" version="6.15.0" targetFramework="net45" />
  <package id="Microsoft.OData.Edm" version="6.15.0" targetFramework="net45" />
  <package id="Microsoft.Spatial" version="6.15.0" targetFramework="net45" />
</packages>

public enum Color
{
    Red = 1,
    Green = 2,
    Blue = 3
}

public class Vehicle
{
    public Guid VehicleId { get; set; }
    [JsonConverter(typeof(StringEnumConverter))]
    public Color? Color { get; set; }
}

[HttpGet]
[Route("vehicles")]
public IHttpActionResult GetVehicles(ODataQueryOptions<Vehicle> options)
{
    var query = dbContext.Vehicle.Select(x => new Vehicle
        {
            VehicleId = x.VehicleId,    // guid type for x.VehicleId
            Color = (Color?)x.ColorId    // nullable int type for x.ColorId
        });

    var odataQuery = options.ApplyTo(query) as IQueryable<object>;

    return Ok(odataQuery.AsEnumerable<Vehicle>());
}

试试？$apply=groupby（（vehicleId）），它就工作了

场景2:

<?xml version="1.0" encoding="utf-8"?>
<packages>
  <package id="Microsoft.AspNet.OData" version="5.9.1" targetFramework="net45" />
  <package id="Microsoft.OData.Core" version="6.15.0" targetFramework="net45" />
  <package id="Microsoft.OData.Edm" version="6.15.0" targetFramework="net45" />
  <package id="Microsoft.Spatial" version="6.15.0" targetFramework="net45" />
</packages>

public enum Color
{
    Red = 1,
    Green = 2,
    Blue = 3
}

public class Vehicle
{
    public Guid VehicleId { get; set; }
    [JsonConverter(typeof(StringEnumConverter))]
    public Color? Color { get; set; }
}

[HttpGet]
[Route("vehicles")]
public IHttpActionResult GetVehicles(ODataQueryOptions<Vehicle> options)
{
    var query = dbContext.Vehicle.Select(x => new Vehicle
        {
            VehicleId = x.VehicleId,    // guid type for x.VehicleId
            Color = (Color?)x.ColorId    // nullable int type for x.ColorId
        });

    var odataQuery = options.ApplyTo(query) as IQueryable<object>;

    return Ok(odataQuery.AsEnumerable<Vehicle>());
}

---

但是使用？$apply=groupby（（color）），这将抛出错误消息（“exceptionMessage”：“参数类型不匹配”）。

以下是来自odata.org的答案

从规范的角度来看，枚举类型是基本类型，所以 它们可以在groupby中使用

但是，这并不保证您的首选工具集已经存在 支持这一点

---

我也有同样的问题，使用ODATA-v4