如何序列化查找<;字符串,字符串>;对象转换为JSON?
我正在尝试通过执行以下操作将查找序列化为JSON:如何序列化查找<;字符串,字符串>;对象转换为JSON?,json,asp.net-web-api,serialization,Json,Asp.net Web Api,Serialization,我正在尝试通过执行以下操作将查找序列化为JSON: Lookup<string, string> productIdsByCategory = prodcuts.ToLookup(p => p.Category, p => p.Id); var response = new ComplexType { PropertyA = productIdsByCategory ... other properties left out ... }; retur
Lookup<string, string> productIdsByCategory = prodcuts.ToLookup(p => p.Category, p => p.Id);
var response = new ComplexType
{
PropertyA = productIdsByCategory
... other properties left out ...
};
return Json(response)
my WebAPI在Postman中的响应如下所示:
{
"PropertyA": [
[
"ProductId_A"
],
[
"ProductId_B"
],
[
"ProductId_C"
]
],
... other properties left out ...
}
JSON响应中不包含键,甚至可以这样做吗?你说得对,Newtonsoft.JSON不能很好地处理
查找。以下代码:
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);
您正确地注意到缺少键名(A
,B
,C
),它似乎被序列化为数组数组
似乎不支持序列化开箱即用的查找,因此您必须编写自己的转换器
我找到了一个,但这需要您事先知道密钥的类型和值
修改后,这将完成以下工作:
// Same as above, up till here
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)
{
// TODO: caching
var keyProp = kvp.GetType().GetProperty("Key");
var keyValue = keyProp.GetValue(kvp, null);
obj.Add(keyValue.ToString(), JArray.FromObject((IEnumerable)kvp));
}
obj.WriteTo(writer);
}
}
作为创建自定义转换器的变通方法,您可以将查找
转换为字典
,Newtonsoft.Json可以很好地使用它
myLookup.ToDictionary(x => x.Key, x => x.ToList());
这是一个很好的解决方法。不幸的是,由于Dictionary对象所涉及的哈希代码计算,它没有那么有效。答案很好。如果有人(如我)正在使用序列化时要使用的自定义设置,则可以将序列化程序
参数添加到序列化IEnumerable的行中<代码>obj.Add(keyValue.ToString(),JArray.FromObject((IEnumerable)kvp,**序列化程序**)代码>
{
"A": ["A1", "A2"],
"B": ["B1"],
"C": ["C1", "C2"]
}
myLookup.ToDictionary(x => x.Key, x => x.ToList());