我想将现有的Enum属性标记为过时,并为相同的功能添加新的Enum属性。因此,我的项目中有两个枚举(新的一个和作废的标记为一个)。
使用jsonconvert.deserializeobject函数序列化此枚举值时,仅从Newtonsoft 11.0以上版本引发以下错误。
InvalidOperationException: Enum name 'stringedit' already exists on enum 'EditingType'.
Newtonsoft.Json.Utilities.EnumUtils.InitializeValuesAndNames(Type enumType) JsonSerializationException: Error converting value "boolean" to type 'Student.Models.EditingType'. Path 'columns[0].editType', line 1, position 3997. Newtonsoft.Json.Serialization.JsonSerializerInternalReader.EnsureType(JsonReader reader, object value, CultureInfo culture, JsonContract contract, Type targetType)
如果我的项目中需要做任何更改,或者有任何计划从序列化功能解决此新错误。
我已使用下面的代码块进行过时的枚举属性序列化。
[DataContract]
public enum EditingType
{
[Obsolete("String property has been deprecated. Use StringEdit property instead")]
[EnumMember(Value = "stringedit")]
String,
[EnumMember(Value = "stringedit")]
StringEdit
}
public class JsonPropertyAttribute : Attribute
{
public JsonPropertyAttribute(string argName)
{
PropertyName = argName;
}
public string PropertyName { get; set; }
}
public class JsonConverterAttribute : Attribute
{
public Type ConverterType
{
get; set;
}
public string ValueType
{
get; set;
}
public JsonConverterAttribute(Type type, string valueType)
{
this.ConverterType = type;
this.ValueType = valueType;
}
public JsonConverterAttribute(Type type)
{
this.ConverterType = type;
}
}
public abstract class Converter
{
protected internal abstract IDictionary<string, object> BuildJsonDictionary(object value);
public abstract string SerializeToJson(object inputObject);
}
public class StringEnumConverter : Converter
{
protected internal override IDictionary<string, object> BuildJsonDictionary(object value)
{
IDictionary<string, object> jsonDictionary = new Dictionary<string, object>();
Type objectType = value.GetType();
FieldInfo member = objectType.GetField(value.ToString(), BindingFlags.Static | BindingFlags.Public);
var attrList = member.GetCustomAttributes(typeof(EnumMemberAttribute), true);
var enumMember = attrList.OfType<EnumMemberAttribute>().FirstOrDefault();
string val = enumMember != null ? enumMember.Value : value.ToString();
jsonDictionary.Add(value.GetType().Name, val);
return jsonDictionary;
}
public override string SerializeToJson(object inputObject)
{
var attrList = inputObject.GetType().GetCustomAttributes(false);
var listAttr = attrList.ToList();
FlagsAttribute flagAttr = attrList.Count() != 0 ? (FlagsAttribute)listAttr.Find(item => item.GetType() == typeof(FlagsAttribute)) : null;
bool flag = (flagAttr != null) ? true : false;
if (flag)
{
int value = (int)inputObject;
return value.ToString();
}
else
{
IDictionary<string, object> enumDictionary = BuildJsonDictionary(inputObject);
object enumValue = enumDictionary.First().Value;
string enumstring = "\"" + enumValue.ToString() + "\"";
return enumstring;
}
}
}
[Serializable]
public class TestClass
{
private EditingType _editingType = EditingType.StringEdit;
[JsonProperty("editType")]
[DefaultValue(EditingType.StringEdit)]
[JsonConverter(typeof(StringEnumConverter))]
public EditingType EditType
{
get { return _editingType; }
set { _editingType = value; }
}
}
下面的反序列化功能将在最新的NewtonSoft.json(11.X版本)中引发错误
public class HomeController : Controller
{
public IActionResult Index()
{
// This function will throws the error
JsonConvert.DeserializeObject("{\"editType\":\"string\"}", typeof(TestClass));
return View();
}
}
谢谢..
答案 0 :(得分:0)
我调查了这,这是预期的行为。现在,Json.NET始终关心EnumMember,并且您拥有重复的值。
如果要自定义其序列化,请实施JsonConverter。我不知道您要如何处理样本中的转换类,但Json.NET不在乎它们。
Quoting Json.NET's author来自@dbc的GitHub链接