转换数据集与多个数据表到JSON [英] Convert DataSet with multiple Datatables to Json

问题描述

我想转换具有在其中多个数据表的数据集。

I want to convert a dataset which has multiple data-tables within it.

以下是本例中，

该数据集X有两个数据表A和b

The dataset X has two data tables A and B

我想要的结果如下，

{
    "type":"A",
    "value":"100",
    "details":[
        {"name":"John", "age":"45", "gender":"M"},
        {"name":"Sebastin", "age":"34", "gender":"M"},
        {"name":"Marc", "age":"23", "gender":"M"},
        {"name":"Natalia", "age":"34", "gender":"F"}
        ]
}

目前我使用Newtonsoft.Json 。是否有可能与Newtonsoft.Json？
如果没有，是否可以与任何其他.NET的Json工具？

Currently I am using Newtonsoft.Json. Is it possible with Newtonsoft.Json? If not, is it possible with any other .net Json tools?

推荐答案

您可以得到你想要的JSON通过实现自定义 JsonConverter 像这样的数据集：

You can get the JSON you want by implementing a custom JsonConverter for the DataSet like this:

class CustomDataSetConverter : JsonConverter
{
    public override bool CanConvert(Type objectType)
    {
        return (objectType == typeof(DataSet));
    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        DataSet x = (DataSet)value;
        JObject jObject = new JObject();
        DataTable a = x.Tables["A"];
        foreach (DataColumn col in a.Columns)
        {
            jObject.Add(col.Caption.ToLower(), a.Rows[0][col].ToString());
        }
        JArray jArray = new JArray();
        DataTable b = x.Tables["B"];
        foreach (DataRow row in b.Rows)
        {
            JObject jo = new JObject();
            foreach (DataColumn col in b.Columns)
            {
                jo.Add(col.Caption.ToLower(), row[col].ToString());
            }
            jArray.Add(jo);
        }
        jObject.Add("details", jArray);
        jObject.WriteTo(writer);
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        throw new NotImplementedException();
    }
}

下面是一个演示：

class Program
{
    static void Main(string[] args)
    {
        DataSet x = new DataSet();
        DataTable a = x.Tables.Add("A");
        a.Columns.Add("Type");
        a.Columns.Add("Value");
        a.Rows.Add("A", "100");
        DataTable b = x.Tables.Add("B");
        b.Columns.Add("Name");
        b.Columns.Add("Age");
        b.Columns.Add("Gender");
        b.Rows.Add("John", "45", "M");
        b.Rows.Add("Sebastian", "34", "M");
        b.Rows.Add("Marc", "23", "M");
        b.Rows.Add("Natalia", "34", "F");

        JsonSerializerSettings settings = new JsonSerializerSettings();
        settings.Converters.Add(new CustomDataSetConverter());
        settings.Formatting = Formatting.Indented;

        string json = JsonConvert.SerializeObject(x, settings);
        Console.WriteLine(json);
    }
}

输出：

Output:

{
  "type": "A",
  "value": "100",
  "details": [
    {
      "name": "John",
      "age": "45",
      "gender": "M"
    },
    {
      "name": "Sebastian",
      "age": "34",
      "gender": "M"
    },
    {
      "name": "Marc",
      "age": "23",
      "gender": "M"
    },
    {
      "name": "Natalia",
      "age": "34",
      "gender": "F"
    }
  ]
}

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