使用 lowerCamelCase 查询 Web API 2.2答案

【问题标题】：Quering Web API 2.2 with lowerCamelCase使用 lowerCamelCase 查询 Web API 2.2
【发布时间】：2014-09-11 22:39:14
【问题描述】：

我正在使用带有 [EnableQuery] 的 Web API 2.2，如下所示：

public class ProductsController : ApiController
{
    private MyContext db = new MyContext();


    [EnableQuery]
    public IQueryable<Product> GetProducts()
    {
        return db.Products;
    }
}

一旦我使用CamelCasePropertyNamesContractResolver，我想执行这样的OData 查询：api/products/?$expand=categories 而不是api/products/?$expand=Categories。

我使用ODataController 测试了 OData v4（我不想使用它，因为 DateTime 属性）并且它工作正常：

ODataConventionModelBuilder builder = new ODataConventionModelBuilder();
builder.EnableLowerCamelCase();

那么，我想知道 ApiController 是否可以做到这一点？

【问题讨论】：

标签： odata asp.net-web-api asp.net-web-api2

【解决方案1】：

您需要执行以下步骤：

定义一个自定义的 EnableQueryAttribute：

public class MyEnableQueryAttribute:EnableQueryAttribute
{
    public override IEdmModel GetModel(Type elementClrType, HttpRequestMessage request,
        HttpActionDescriptor actionDescriptor)
    {
        // Get model for the request
        IEdmModel model = request.ODataProperties().Model;

        if (model == null)
        {
            // user has not configured anything or has registered a model without the element type
            // let's create one just for this type and cache it in the action descriptor
            model = actionDescriptor.Properties.GetOrAdd("System.Web.OData.Model+" + elementClrType.FullName, _ =>
            {
                ODataConventionModelBuilder builder =
                    new ODataConventionModelBuilder(actionDescriptor.Configuration, isQueryCompositionMode: true);
                builder.EnableLowerCamelCase();
                EntityTypeConfiguration entityTypeConfiguration = builder.AddEntityType(elementClrType);
                builder.AddEntitySet(elementClrType.Name, entityTypeConfiguration);
                IEdmModel edmModel = builder.GetEdmModel();
                Contract.Assert(edmModel != null);
                return edmModel;
            }) as IEdmModel;
        }

        Contract.Assert(model != null);
        return model;
    }
}

将其添加到控制器中的操作中：

public class ProductsController : ApiController
{
    [MyEnableQuery]
    public IHttpActionResult Get()
    {
        IList<Product> products=new List<Product>();
        products.Add(new Product() { Id = 1, Name = "Name1",Category=new Category(){Id=1,Name="Category1" }});
        products.Add(new Product() { Id = 2, Name = "Name2", Category = new Category() { Id = 2, Name = "Category2" } });


        return Ok(products.AsQueryable<Product>());
    }
}

那么就可以用驼峰式查询了：

GET http://localhost:12568/api/Products?$expand=category

我已将整个解决方案放在这里：https://github.com/tanjinfu/WebApiODataSamples/tree/master/EnableCamelCaseForApiController，仅供参考。

【讨论】：