对平面列表进行分组并输出分层 JSON

Question

我的结果集如下所示：

需要用嵌套组格式化成层次结构的json：

     [
        {
            areaName: "Latam",
            subsidaries: [
                { areaName: "Ecuador", id: 1 },
                { areaName: "Peru", id: 3 },
                { areaName: "Jamaica", id: 4 },
                { areaName: "Venezuela", id: 5 },
                { areaName: "BCBB", id: 6 }
            ]
        },
        {
            areaName: "APAC",
            subsidaries: [
                { areaName: "Brunei", id: 1 },
                { areaName: "Sri Lanka", id: 31 },
                { areaName: "(APAC Sub Not Specified)", id: 1 },
                { areaName: "Korea", id: 231 },
                { areaName: "Malaysia", id: 61 },
                { areaName: "Indonesia", id: 61 },
                { areaName: "Philippines", id: 31 },
                { areaName: "Singapore", id: 3231 },
                { areaName: "Australia", id: 621 },
                { areaName: "New Zealand", id: 231 },
                { areaName: "Vietnam", id: 431 },
                { areaName: "Thailand", id: 99 }
            ]
        }],

我最初的想法是使用 linq 查询对数据进行分组：

    public ActionResult Index()
    {
        var model = Repository.GetGeoSubsidiaryHierarchy();

        foreach (var line in GroupedItems(model)
           .Select(group => new
           {
               AreaName = group.Key,
               Count = group.Count()
           }).OrderBy(x => x.AreaName))
        {
            Response.Write( String.Format( "{0} {1}", line.AreaName, line.Count) );
        }

        return View("Index", model);
    }

    private static IEnumerable<IGrouping<string, GeoSubsidiary>> GroupedItems(List<GeoSubsidiary> model)
    {
        var ret = model.ToList().GroupBy(area => area.AreaName);


        return ret;
    }

但我不清楚如何在分组后序列化此列表。此外，我对自己的分组技巧没有信心，因为我对迭代每个分组行的子选择有点模糊（此代码：.Select(group => new)...）。

我考虑的其他选项是使用 DataAnnotations/DataContracts 和自定义注释类，利用 Newtonsoft JSON.NET 的一些高级功能，或者使用字典并将其与分组的行一起加载。

如果有人能推荐处理分组数据和 JSON 的最佳实践并帮助我开始编写代码以输出此分组层次结构（我手工构建的示例 JSON 数据，但正是我想要的），我将不胜感激输出）。

为了完整起见，我应该提一下，我的最终目标是创建一个出色的 Kendo 分层数据源 javascript 对象：http://docs.kendoui.com/api/framework/hierarchicaldatasource

Answer 1

如果您只需要显示数据，您总是可以从您的服务中获取所有记录，并在 javascript 中进行分组，然后将您的分层数据源绑定到该数据源。

示例http://jsbin.com/uQuLUwE/2/edit（我只是将它绑定到树视图以便显示）

如果没有，您始终可以创建两个数据源，一个用于根项，一个用于子项。根项需要提取不同的 AreaNames，然后需要过滤 childItems 数据源以获得正确的 AreaName。

Answer 2

感谢您的建议 - 我最终选择了一个可能过于复杂的 c# 方法

public class HierarchalDataController : BaseController
{

    internal class ChildNode
    {
        public string areaName { get; set; }
        public int id { get; set; }
    }

    internal class Area
    {
        public string areaName { get; set; }
        public List<ChildNode> subsidaries { get; set; }
    }

    public ContentResult GetAreaContent()
    {
        var areas = Repository.GetGeoSubsidiaryHierarchy();
        var groupedAreas = areas.GroupBy(area => area.AreaName);
        var subareas = new List<Area>();

        foreach (var parentArea in groupedAreas)
        {
            var subsidiaries = new List<ChildNode>();
            var subs = areas.Where(x => x.AreaName == parentArea.Key).ToList();
            subsidiaries.AddRange(subs.Select(sub => new ChildNode { id = sub.SubsidiaryId, areaName = sub.SubsidiaryName }));
            var area = new Area { areaName = parentArea.Key, subsidaries = subsidiaries };
            subareas.Add(area);
        }

        var retval = JsonConvert.SerializeObject(subareas, Formatting.Indented);
        return Content(retval, "application/json");
    }

    public ContentResult GetScenarioContent()
    {
        var areas = Repository.GetScenarioHierarchy();
        var groupedAreas = areas.GroupBy(area => area.FunctionalAreaID);
        var subareas = new List<Area>();

        foreach (IGrouping<int, Scenario> parentArea in groupedAreas)
        {
            var subsidiaries = new List<ChildNode>();
            var subs = areas.Where(x => x.FunctionalAreaID== parentArea.Key).ToList();
            subsidiaries.AddRange(subs.Select(sub => new ChildNode { id = sub.FunctionalAreaID, areaName = sub.ScenarioName}));
            var scenario = parentArea.FirstOrDefault();

            if (scenario != null)
            {
                var area = new Area { areaName = scenario.FunctionalAreaName, subsidaries = subsidiaries }; // hack
                subareas.Add(area);
            }
        }

        var retval = JsonConvert.SerializeObject(subareas, Formatting.Indented);
        return Content(retval, "application/json");
    }

    /// <summary>
    /// Simply a flat-list of products. 
    /// </summary>
    /// <returns></returns>
    public ContentResult GetProductContent()
    {
        var subareas = new List<Area>();
        foreach (var product in Repository.GetProductList())
        {
            subareas.Add(new Area
            {
                areaName = product.ProductName,
                subsidaries = new List<ChildNode>()
            });
        }

        var retval = JsonConvert.SerializeObject(subareas, Formatting.Indented);
        return Content(retval, "application/json");
    }


}