我当前正在学习如何使用MS’s ASP.NET web API guide 创建OData服务.在“助手”部分中,尝试获取HttpRequestMessage.ODataProperties().PathHandler或… Model字段会引发上述错误.根据MS’s documentation,导入System.Web.OData.Extensions应该正确.

对于Odata.Client使用6.13.0,对于Odata.Core使用7.0.0.

相关代码,基本上与Web api指南为1：1：

using Microsoft.OData;
using Microsoft.OData.UriParser;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Web.Http.Routing;
using System.Web.OData.Extensions;

namespace WebApiGuide {
public static class Helpers
{
    public static TKey GetKeyFromUri<TKey>(HttpRequestMessage Request, Uri uri)
    {
        if (uri == null)
        {
            throw new ArgumentNullException("uri");
        }

        var urlHelper = Request.GetUrlHelper() ?? new UrlHelper(Request);

        string serviceRoot = urlHelper.CreateODataLink(
            Request.ODataProperties().RouteName,
            Request.ODataProperties().PathHandler, new List<ODataPathSegment>());
        var odataPath = Request.ODataProperties().PathHandler.Parse(
            Request.ODataProperties().Model,
            serviceRoot, uri.LocalPath);

        var keySegment = odataPath.Segments.OfType<KeyValuePathSegment>().FirstOrDefault();
        if (keySegment == null)
        {
            throw new InvalidOperationException("The link does not contain a key");
        }

        var value = ODataUriUtils.ConvertFromUriLiteral(keySegment.Value, ODataVersion.V4);
        return (TKey)value;
    }
}
}

编辑：如果它使问题更加具体,则System.Web.OData.Routing中的KeyValuePathSegment也有相同的问题

解决方法:

对于其他出于相同原因而在此处结束的人,这是我的代码(显然keySegment也已更改,并且Value包含已转换的对象)：

public static TKey GetKeyFromUri<TKey>(HttpRequestMessage request, Uri uri)
{
    if (uri == null)
    {
        throw new ArgumentNullException(nameof(uri));
    }

    var urlHelper = request.GetUrlHelper() ?? new UrlHelper(request);
    var serviceRoot = urlHelper.CreateODataLink(request.ODataProperties().RouteName, request.GetPathHandler(), new List<ODataPathSegment>());
    var odataPath = request.GetPathHandler().Parse(serviceRoot, uri.LocalPath, request.GetRequestContainer());

    var keySegment = odataPath.Segments.OfType<KeySegment>().FirstOrDefault();
    if (keySegment?.Keys?.FirstOrDefault() == null)
    {
        throw new InvalidOperationException("The link does not contain a key.");
    }

    return (TKey)keySegment.Keys.First().Value;
}