Question

我有一个看起来像这样的json字符串（简化版）：

{"Statistics":[
                {"Direction":"2-WAY","AADT":8129,"BC":254},
                {"Direction":"NEG","AADT":3956,"BC":124},
                {"Direction":"POS","AADT":4173,"BC":128}
            ]
}

我还启动了一个c＃程序：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Newtonsoft.Json.Linq;
namespace TrafficCounterJSON {
    class Program {
        static void Main(string[] args) {
            string jsonString = "{\"Statistics\":[{\"Direction\":\"2-WAY\",\"AADT\":8129},{\"Direction\":\"NEG\",\"AADT\":3956}]}";
            var jObjectt = Newtonsoft.Json.Linq.JObject.Parse(jsonString);
        }//main

   }
}

我想知道如何使用Newtonsoft.Json.Linq来查询json字符串中的项目，如下所示：

我想要“ Direction = NEG”的所有统计信息行

我似乎无法找出正确的语法来获得这些结果（通过select ... where子句）

因此，根据下面的输入，我终于为json数据构建了一个模型（我使用了该网站：http://json2csharp.com）

下面是json的完整版本：

 {  "RequestId":"068f38ed-532c-442c-aae7-748112926b0d",

    "Parameters":{"AgencyId":25,"LocalId":"710541"},

    "Statistics":[
        {"LastCollectionDate":"\/Date(1479272400000-0500)\/","Direction":"2-WAY","AADT":8129,"BC":254,"TimePeriod":"AM","PeakHour":"07:00 - 08:00","PeakHourVolume":832,"CommercialPeakHourVolume":24},
        {"LastCollectionDate":"\/Date(1479272400000-0500)\/","Direction":"2-WAY","AADT":8129,"BC":254,"TimePeriod":"PM","PeakHour":"16:00 - 17:00","PeakHourVolume":863,"CommercialPeakHourVolume":16},
        {"LastCollectionDate":"\/Date(1479272400000-0500)\/","Direction":"NEG","AADT":3956,"BC":124,"TimePeriod":"AM","PeakHour":"07:00 - 08:00","PeakHourVolume":234,"CommercialPeakHourVolume":9},
        {"LastCollectionDate":"\/Date(1479272400000-0500)\/","Direction":"NEG","AADT":3956,"BC":124,"TimePeriod":"PM","PeakHour":"16:00 - 17:00","PeakHourVolume":525,"CommercialPeakHourVolume":7},
        {"LastCollectionDate":"\/Date(1479272400000-0500)\/","Direction":"POS","AADT":4173,"BC":128,"TimePeriod":"AM","PeakHour":"07:00 - 08:00","PeakHourVolume":598,"CommercialPeakHourVolume":15},
        {"LastCollectionDate":"\/Date(1479272400000-0500)\/","Direction":"POS","AADT":4173,"BC":128,"TimePeriod":"PM","PeakHour":"16:00 - 17:00","PeakHourVolume":338,"CommercialPeakHourVolume":9}
    ],
    "AadtHistory":[
        {"Year":2017,"Aadt":8202,"Source":"Grown from 2016"},
        {"Year":2016,"Aadt":8129,"Source":null},
        {"Year":2015,"Aadt":6194,"Source":"Grown from 2014"},
        {"Year":2014,"Aadt":6061,"Source":null},
        {"Year":2013,"Aadt":5538,"Source":"Grown from 2012"},
        {"Year":2012,"Aadt":5617,"Source":"Grown from 2011"},
        {"Year":2011,"Aadt":5623,"Source":null},
        {"Year":2000,"Aadt":6090,"Source":"Flowmap"},
        {"Year":1997,"Aadt":5210,"Source":"Flowmap"},
        {"Year":1992,"Aadt":5360,"Source":"Flowmap"},
        {"Year":1988,"Aadt":4330,"Source":"Flowmap"}]
    }

这是我现在使用的对应模型：

public class Parameters {
    public int AgencyId { get; set; }
    public string LocalId { get; set; }
}

public class Statistic {
    public DateTime LastCollectionDate { get; set; }
    public string Direction { get; set; }
    public int AADT { get; set; }
    public int BC { get; set; }
    public string TimePeriod { get; set; }
    public string PeakHour { get; set; }
    public int PeakHourVolume { get; set; }
    public int CommercialPeakHourVolume { get; set; }
}

public class AadtHistory {
    public int Year { get; set; }
    public int Aadt { get; set; }
    public string Source { get; set; }
}

public class RootObject {
    public string RequestId { get; set; }
    public Parameters Parameters { get; set; }
    public List<Statistic> Statistics { get; set; }
    public List<AadtHistory> AadtHistory { get; set; }
}

这里是我使用的统计信息数组（来自json字符串）中的行的拉数据的一小段代码

var myObject = JsonConvert.DeserializeObject<RootObject>(jsonResponseString);
     foreach (Statistic stat in myObject.Statistics) {
       Console.WriteLine("AADT:" + stat.AADT);                        
}

Answer 1

添加模型后，您几乎就在那儿。您现在可以使用Linq根据方向进行过滤。

 var filteredList = myObject.Statistics.Where(x=>x.Direction == "NEG");

使用Newtonsoft.Json.Linq

1 个答案: