我有一个包含枚举属性的类，在使用JavaScriptSerializer序列化对象时，我的json结果包含枚举的整数值，而不是它的字符串“name”。有没有一种方法来获得枚举作为字符串在我的json而不必创建一个自定义JavaScriptConverter?也许有一个属性，我可以装饰枚举定义，或对象属性?
举个例子:
enum Gender { Male, Female }
class Person
{
int Age { get; set; }
Gender Gender { get; set; }
}
期望的JSON结果:
{ "Age": 35, "Gender": "Male" }
理想情况下，用内置的。net框架类来寻找答案，如果没有可能的替代方案(如Json.net)也是受欢迎的。
当前回答
这个版本的Stephen的回答没有改变JSON中的名称:
[DataContract(
Namespace =
"http://schemas.datacontract.org/2004/07/Whatever")]
class Person
{
[DataMember]
int Age { get; set; }
Gender Gender { get; set; }
[DataMember(Name = "Gender")]
string GenderString
{
get { return this.Gender.ToString(); }
set
{
Gender g;
this.Gender = Enum.TryParse(value, true, out g) ? g : Gender.Male;
}
}
}
其他回答
new JavaScriptSerializer().Serialize(
(from p
in (new List<Person>() {
new Person()
{
Age = 35,
Gender = Gender.Male
}
})
select new { Age =p.Age, Gender=p.Gender.ToString() }
).ToArray()[0]
);
注意，当存在Description属性时，没有序列化的答案。
下面是支持Description属性的实现。
public class CustomStringEnumConverter : Newtonsoft.Json.Converters.StringEnumConverter
{
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
Type type = value.GetType() as Type;
if (!type.IsEnum) throw new InvalidOperationException("Only type Enum is supported");
foreach (var field in type.GetFields())
{
if (field.Name == value.ToString())
{
var attribute = Attribute.GetCustomAttribute(field, typeof(DescriptionAttribute)) as DescriptionAttribute;
writer.WriteValue(attribute != null ? attribute.Description : field.Name);
return;
}
}
throw new ArgumentException("Enum not found");
}
}
枚举:
public enum FooEnum
{
// Will be serialized as "Not Applicable"
[Description("Not Applicable")]
NotApplicable,
// Will be serialized as "Applicable"
Applicable
}
用法:
[JsonConverter(typeof(CustomStringEnumConverter))]
public FooEnum test { get; set; }
对于VB.net，我找到了以下作品:
Dim sec = New Newtonsoft.Json.Converters.StringEnumConverter()
sec.NamingStrategy() = New Serialization.CamelCaseNamingStrategy
Dim JSON_s As New JsonSerializer
JSON_s.Converters.Add(sec)
Dim jsonObject As JObject
jsonObject = JObject.FromObject(SomeObject, JSON_s)
Dim text = jsonObject.ToString
IO.File.WriteAllText(filePath, text)
对于任何在22年5月就需要。net 6解决方案并且仍在使用Newtonsoft的人来说，你可以像这样全局注册转换器:
var builder = WebApplication.CreateBuilder(args);
...
builder.Services.AddControllers(options => options.RespectBrowserAcceptHeader = true)
.AddNewtonsoftJson(opt =>
{
opt.SerializerSettings.ContractResolver = new DefaultContractResolver();
opt.SerializerSettings.Converters.Add(new Newtonsoft.Json.Converters.StringEnumConverter());
})
.AddXmlSerializerFormatters()
.AddXmlDataContractSerializerFormatters();
不确定这是否仍然相关，但我必须直接写一个json文件，我想出了以下拼凑几个stackoverflow的答案在一起
public class LowercaseJsonSerializer
{
private static readonly JsonSerializerSettings Settings = new JsonSerializerSettings
{
ContractResolver = new LowercaseContractResolver()
};
public static void Serialize(TextWriter file, object o)
{
JsonSerializer serializer = new JsonSerializer()
{
ContractResolver = new LowercaseContractResolver(),
Formatting = Formatting.Indented,
NullValueHandling = NullValueHandling.Ignore
};
serializer.Converters.Add(new Newtonsoft.Json.Converters.StringEnumConverter());
serializer.Serialize(file, o);
}
public class LowercaseContractResolver : DefaultContractResolver
{
protected override string ResolvePropertyName(string propertyName)
{
return Char.ToLowerInvariant(propertyName[0]) + propertyName.Substring(1);
}
}
}
它确保我所有的json键小写开始根据json“规则”。将其格式化为干净的缩进格式，并忽略输出中的空值。此外，通过添加一个StringEnumConverter，它打印枚举及其字符串值。
就我个人而言，我发现这是我能想到的最干净的方法，而不必用注释弄脏模型。
用法:
internal void SaveJson(string fileName)
{
// serialize JSON directly to a file
using (StreamWriter file = File.CreateText(@fileName))
{
LowercaseJsonSerializer.Serialize(file, jsonobject);
}
}
