您是正确的,Newtonsoft.Json 对 Lookup<TKey, TElement>
处理得不好。下面是代码:
var input = new List<string>()
{
"A1",
"A2",
"B1",
"C1",
"C2"
};
var lookup = input.ToLookup(i => i[0], i => i);
var json = JsonConvert.SerializeObject(lookup);
Console.WriteLine(json);
序列化为:
[["A1","A2"],["B1"],["C1","C2"]]
您正确地指出了缺少关键名称(
A
,
B
,
C
),它似乎被序列化为一个数组的数组。
似乎没有内置的支持来序列化查找,因此您将不得不编写自己的转换器。
我在这里找到了一个
转换器,但这需要您事先知道键和值的类型。
修改后,这就完成了工作:
var json = JsonConvert.SerializeObject(lookup, new LookupSerializer());
Console.WriteLine(json);
}
}
public class LookupSerializer : JsonConverter
{
public override bool CanConvert(Type objectType)
{
var result = objectType.GetInterfaces().Any(a => a.IsGenericType
&& a.GetGenericTypeDefinition() == typeof(ILookup<,>));
return result;
}
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
throw new NotImplementedException();
}
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
var obj = new JObject();
var enumerable = (IEnumerable)value;
foreach (object kvp in enumerable)
{
var keyProp = kvp.GetType().GetProperty("Key");
var keyValue = keyProp.GetValue(kvp, null);
obj.Add(keyValue.ToString(), JArray.FromObject((IEnumerable)kvp));
}
obj.WriteTo(writer);
}
}
输出:
{
"A": ["A1", "A2"],
"B": ["B1"],
"C": ["C1", "C2"]
}