我正在使用一个 API,它以一种不同于我习惯处理的方式返回结果给我,而且似乎是非标准的。
例如,以下是客户数据的片段:
{
"CustomerID": {
"value": "EXAMPLE"
},
"CustomerCurrencyID": {
"value": "USD"
}
}
那个“值”属性似乎非常没有必要,所以我想看看我是否可以一起绕过它并将该 JSON 反序列化为一个对象,如下所示:
class Customer {
public string CustomerID { get; set; }
public string CustomerCurrencyID { get; set; }
}
我目前正在编写一个自定义的 JsonConverter 来处理这个问题,所以如果我走在正确的道路上,请告诉我,但这里的任何提示/技巧将不胜感激!
答案 0 :(得分:2)
您可以使用通用的 custom JsonConverter
执行此操作,如下所示:
public class WrapWithValueConverter<TValue> : JsonConverter
{
// Here we take advantage of the fact that a converter applied to a property has highest precedence to avoid an infinite recursion.
class DTO { [JsonConverter(typeof(NoConverter))] public TValue value { get; set; } public object GetValue() => value; }
public override bool CanConvert(Type objectType) => typeof(TValue).IsAssignableFrom(objectType);
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
=> serializer.Serialize(writer, new DTO { value = (TValue)value });
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
=> serializer.Deserialize<DTO>(reader)?.GetValue();
}
public class NoConverter : JsonConverter
{
// NoConverter taken from this answer https://stackoverflow.com/a/39739105/3744182
// By https://stackoverflow.com/users/3744182/dbc
// To https://stackoverflow.com/questions/39738714/selectively-use-default-json-converter
public override bool CanConvert(Type objectType) { throw new NotImplementedException(); /* This converter should only be applied via attributes */ }
public override bool CanRead => false;
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer) => throw new NotImplementedException();
public override bool CanWrite => false;
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer) => throw new NotImplementedException();
}
然后您可以将其应用到您的模型中,如下所示:
class Customer {
[JsonConverter(typeof(WrapWithValueConverter<string>))]
public string CustomerID { get; set; }
[JsonConverter(typeof(WrapWithValueConverter<string>))]
public string CustomerCurrencyID { get; set; }
}
演示小提琴 #1 here。
或者,如果您希望将所有字符串包装在一个 {"value": <string value>}
对象中,您可以在序列化和反序列化时将转换器添加到 JsonSerializerSettings.Converters
:
var settings = new JsonSerializerSettings
{
Converters = { new WrapWithValueConverter<string>() },
};
var model = JsonConvert.DeserializeObject<Customer>(json, settings);
var json2 = JsonConvert.SerializeObject(model, Formatting.Indented, settings);
演示小提琴 #2 here。
如果您的值是 enum
并且您想将其序列化为字符串,则可以使用以下命令将 NoConverter
替换为 StringEnumConverter
:
public class WrapEnumWithValueConverter<TEnum> : JsonConverter where TEnum: Enum
{
// Here we take advantage of the fact that a converter applied to a property has highest precedence to avoid an infinite recursion.
class DTO { [JsonConverter(typeof(StringEnumConverter))] public TEnum value { get; set; } public object GetValue() => value; }
public override bool CanConvert(Type objectType) => typeof(TEnum).IsAssignableFrom(objectType);
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
=> serializer.Serialize(writer, new DTO { value = (TEnum)value });
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
=> serializer.Deserialize<DTO>(reader)?.GetValue();
}
演示小提琴 #3 here。