c# - 合并 2 个 JSON 文件 Newtonsoft

Question

我有 2 个 json 文件或字符串，我想根据 ID 合并它们。就像加入 sql 一样。这是示例:

这是 Json 1:

{
    "City": [{
        "CityId": 9,
        "CityName": "Kukes"
    }, {
        "CityId": 18,
        "CityName": "Tirana"
    }, {
        "CityId": 19,
        "CityName": "Vlore"
    }, {
        "CityId": 22,
        "CityName": "temp"
    }]
}

这是我的 json 2:

{
    "Citizen": [{
        "CitizenId": 38,
        "CitizenLastName": "Bale",
        "CitizenName": "Christian",
        "City_Id": 19
    }, {
        "CitizenId": 39,
        "CitizenLastName": "ttrtrt",
        "CitizenName": "test",
        "City_Id": 18
    }, {
        "CitizenId": 42,
        "CitizenLastName": "Freeman",
        "CitizenName": "Morgan",
        "City_Id": 9
    }, {
        "CitizenId": 43,
        "CitizenLastName": "Snow",
        "CitizenName": "Jon",
        "City_Id": 9
    }, {
        "CitizenId": 44,
        "CitizenLastName": "test2",
        "CitizenName": "test",
        "City_Id": 9
    }]
}

我希望它合并到一个基于 id 的 json 文件或字符串中，如下所示:

{
    "City":
    [
        {
            "CityId":9,
            "CityName":"Kukes",
            "Citizens" : [{"CitizenId":42,"CitizenLastName":"Freeman","CitizenName":"Morgan","City_Id":9},{"CitizenId":43,"CitizenLastName":"Snow","CitizenName":"Jon","City_Id":9},{"CitizenId":44,"CitizenLastName":"test2","CitizenName":"test","City_Id":9}]
        },
        {
            "CityId":18,
            "CityName":"Tirana",
            "Citizens" : [{"CitizenId":39,"CitizenLastName":"ttrtrt","CitizenName":"test","City_Id":18}]
        },
        {
            "CityId":19,
            "CityName":"Vlore",
            "Citizens" : [{"CitizenId":38,"CitizenLastName":"Bale","CitizenName":"Christian","City_Id":19}]
        },
        {
            "CityId":22,
            "CityName":"temp",
            "Citizens" : []
        }
    ]
}

我试了一整天，还是一无所获。你知道如何用 Newtonsoft 做到这一点吗？还是有其他办法？但我希望使用 newtonsoft。

Answer 1

您可以使用 LINQ to JSON 执行此操作, 使用 ToLookup()查找给定城市的所有公民:

var cities = JToken.Parse(cityJson);
var citizens = JToken.Parse(citizenJson);

var lookup = citizens.SelectTokens("Citizen[*]").ToLookup(c => (string)c["City_Id"]);

foreach (var city in cities.SelectTokens("City[*]"))
{
    city["Citizens"] = new JArray(lookup[(string)city["CityId"]]);
}

原型(prototype) fiddle .

要从文件加载 JSON，然后再保存回来，请参阅 Read JSON from a file和 Write JSON to a file .