带有可选参数的 OData 路由答案

【问题标题】：OData Routing with Optional Parameter带有可选参数的 OData 路由
【发布时间】：2015-10-05 18:12:49
【问题描述】：

我有一个 OData (v3) Web API 2 项目，它是另一个 wcf Web 服务的包装器。此 odata 连接的预期客户端是 SharePoint 2013。我正在此包装器中创建 CRUD 操作，并注意到当要求 sharepoint 删除某些内容时，它会以这种格式发送请求：/Entity(Identity=XX) 而不是正常的 /Entity (XX) 我工作正常。我需要能够在不破坏另一个请求的情况下处理该请求。这是我的代码：

    public IHttpActionResult GetSchool([FromODataUri] int key, ODataQueryOptions<School> queryOptions)
    {
        // validate the query.
        try
        {
            queryOptions.Validate(_validationSettings);
        }
        catch (ODataException ex)
        {
            return BadRequest(ex.Message);
        }
        SchoolDataSource data = new SchoolDataSource();
        var result = data.GetByID(key);
        return Ok<School>(result);
        //return StatusCode(HttpStatusCode.NotImplemented);
    }

这适用于 /Schools(1) 的请求，但不适用于 /Schools(ID=1)。我试过添加： [Route("Schools(ID={key}")] 这使得 /Schools(ID=1) 路由工作，但几乎破坏了其他所有内容（406 错误）。我尝试添加上述属性和 [Route("Schools({key})")]看看我是否能让它们都工作，但它也不能正常工作。我对此很陌生，并希望至少能找到一些方向。这是我的 WebApiConfig：

        config.MapHttpAttributeRoutes();
        config.EnableQuerySupport();
        config.IncludeErrorDetailPolicy = IncludeErrorDetailPolicy.Always;

        // Web API configuration and services
        ODataConventionModelBuilder builder = new ODataConventionModelBuilder();
        builder.EntitySet<School>("Schools");
        builder.DataServiceVersion = new Version("2.0");
        config.Routes.MapODataRoute("odata", null, builder.GetEdmModel());
        // Web API routes


        config.Routes.MapHttpRoute(
            name: "DefaultApi",
            routeTemplate: "api/{controller}/{id}",
            defaults: new { id = RouteParameter.Optional }
        );

我得到的错误： 406 如果我设置了路由属性。如果我没有设置路由属性，则为 500。似乎我的服务不知道如何处理参数，除非我指定它，但如果我这样做，所有调用都会得到 406 错误。

【问题讨论】：

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

【解决方案1】：

可能不是最好的方法，但使它适用于此类：

public class SharePointRoutingConvention : EntitySetRoutingConvention
{
    public override string SelectAction(ODataPath odataPath, HttpControllerContext context,
        ILookup<string, HttpActionDescriptor> actionMap)
    {
        //Gets the entity type
        IEdmEntityType entityType = odataPath.EdmType as IEdmEntityType;

        //makes sure the format is correct
        if (odataPath.PathTemplate == "~/entityset/key")
        {
            //parses out the path segment (Identity=X)
                            KeyValuePathSegment segment = odataPath.Segments[1] as KeyValuePathSegment;

            //Gets the verb from the request header
            string actionName = context.Request.Method.ToString();

            // Add keys to route data, so they will bind to action parameters.
            KeyValuePathSegment keyValueSegment = odataPath.Segments[1] as KeyValuePathSegment;

            //Checks to see if the "Identity=" part is in the url
            if (keyValueSegment.Value.Contains("Identity="))
            {
                //removes the extra text
                context.RouteData.Values[ODataRouteConstants.Key] = keyValueSegment.Value.Replace("Identity=", "");
            }
            else
            {
                //parses it normally
                context.RouteData.Values[ODataRouteConstants.Key] = keyValueSegment.Value;
            }

            //returns the verb
            return actionName;

        }
        // Not a match.
        return null;
    }
}

并对 webapiconfig 进行更改：

        var conventions = ODataRoutingConventions.CreateDefault();

        //adding the custom odata routing convention
        conventions.Insert(0, new SharePointRoutingConvention());



     config.Routes.MapODataRoute(
            routeName: "odata",
            routePrefix: null,//this is so that you can type the base url and get metadata back (http://localhost/) 
            model: builder.GetEdmModel(),
            pathHandler: new DefaultODataPathHandler(),
            routingConventions: conventions //this assigns the conventions to the route
            );

【讨论】：