c# - 构造 JSON 有效负载

Question

我有下表：

我想执行一个序列化的 LINQ 查询：

JSON：

{
  "product-list": {
    "products": [
        {
          "P_Flavor": [
            "Berry",
            "Cedar",
            "Cherry",
            "Coffee"
          ],
          "P_Winery": [
            "Lyeth"
          ],
          "P_Body": [
            "Elegant",
            "Firm",
            "Firm Tannins",
            "Polished",
            "Supple",
            "Tannins"
          ],
          "P_Name": "A Red Blend",
          "P_DateReviewed": "08/31/95",
          "P_WineID": 34699,
          "P_Score": 5,
        }
    ]
  }
}

我通常JavaScriptSerializer会这样做，但是我想构建自己的 JSON 有效负载。

IList<record_property> recList = (from c in entities.record_property
                                    select c).ToList();

var json = new JavaScriptSerializer().Serialize(recList);

最好的方法是什么？

Answer 1

可能有一种更快/更简洁的方法来做到这一点，但我是通过将 aJavaScriptConverter与辅助类型结合来实现的。

转换器（比看起来简单，灵感来自这里）：

private class RecordPropertyJavaScriptConverter : JavaScriptConverter
{
    private static readonly Type[] _supportedTypes = new[]
    {
        typeof(record_group)
    };

    public override IEnumerable<Type> SupportedTypes
    {
        get { return _supportedTypes; }
    }

    public override object Deserialize(IDictionary<string, object> dictionary, Type type, JavaScriptSerializer serializer)
    {
        if (type == typeof(record_group))
        {
            record_group obj = new record_group();

            var kvp = dictionary.Single();

            obj.Key = kvp.Key;
            obj.Values = serializer.ConvertToType<IEnumerable<object>>(kvp.Value);

            return obj;
        }

        return null;
    }

    public override IDictionary<string, object> Serialize(object obj, JavaScriptSerializer serializer)
    {
        var dataObj = obj as record_group;
        if (dataObj != null)
        {
            return new Dictionary<string, object>
            {
                {dataObj.Key,  dataObj.Values}
            };
        }
        return new Dictionary<string, object>();
    }
}

助手类型：

private class record_group
{
    public string Key;
    public IEnumerable<object> Values;
}

序列化代码：

var groups = recList.GroupBy(r => r.Key)
                    .Select(g => new record_group { Key = g.Key, Values = g.Select(r => r.Value) });

JavaScriptSerializer serializer = new JavaScriptSerializer();
serializer.RegisterConverters(new [] {new RecordPropertyJavaScriptConverter()});
string json = serializer.Serialize(groups);

输出（带有一些标签，我添加了换行符）：

[{"P_Flavor":["Berry","Cedar","Cherry","Coffee"]},
 {"P_Winery":["Lyeth"]},
 {"P_Body":["Elegant","Firm","Firm Tannins","Polished","Supple","Tannins"]},
 {"P_Name":["A Red Blend"]},
 {"P_DateReviewed":["08/31/95"]},
 {"P_WineID":[34699]},
 {"P_Score":[5]}]

然后可以进行反序列化（使用与上面相同的序列化程序实例），如下所示：

var deserialized = serializer.Deserialize<IEnumerable<record_group>>(json);
var properties = deserialized.SelectMany(g => g.Values.Select(v => new record_property { Key = g.Key, Value = v }));