基于JSON.NET为Enum实现数据与界面分离
基于JSON.NET为Enum实现数据与界面分离在日常做项目过程中，一直很烦恼枚举值显示问题。当添加，修改，删除枚举值时，都要去修改界面原先的中文表述，很是麻烦。今天针对Enum做相应的扩展，并实现Newtonsoft.Json（JSON.NET）JsonConverter个性化定制，使数据与界面分离，此方法适用于依赖Json数据结构传输数据的应用开发，例如：web 开发。
1、首先，实现Localization属性标签
[AttributeUsage(AttributeTargets.Field)] public class LocalizationAttribute : Attribute { public LocalizationAttribute(string showValue) { ShowValue = showValue; } public string ShowValue { get; set; } }
2、实现JsonConverter，将原先enum转换结果改成｛Value:[int],ShowValue:[string]｝
public class EnumLocalizationConverter : JsonConverter { public override bool CanConvert(Type objectType) { return objectType.IsEnum; } public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer) { try { var value = serializer.Deserialize<EnumLocalization>(reader); return Enum.Parse(objectType, value.Value.ToString()); } catch { } return Enum.Parse(objectType, serializer.Deserialize(reader).ToString()); } public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer) { var type = value.GetType(); var fieldName = type.GetEnumName(value); if (fieldName != null) { var localozation = type.GetField(fieldName).GetCustomAttribute<LocalizationAttribute>(); serializer.Serialize(writer, new { Value = value, ShowValue = localozation.ShowValue }); } else { serializer.Serialize(writer, new EnumLocalization() { Value = value, ShowValue = string.Empty }); } } }
public class EnumLocalization { public object Value { get; set; } public string ShowValue { get; set; } }
3、实现Enum静态扩展功能（获取标记上的文本）
public static class EnumLocalizationExtensions { public static string ToLocalizationString(this Enum _this) { var type = _this.GetType(); return type.GetField(_this.ToString()).GetCustomAttribute<LocalizationAttribute>().ShowValue; } public static IDictionary<int, string> GetLocalizations(this Enum _this) { var type = _this.GetType(); var arr = type.GetEnumValues(); Dictionary<int, string> dict = new Dictionary<int, string>(); foreach (int i in arr) { var enumValue = Enum.Parse(type, i.ToString()) as Enum; dict.Add(i, enumValue.ToLocalizationString()); } return dict; } }
4、使用
public enum LogType { [Localization("登录")] Login = 1, [Localization("退出")] Exit = 2, [Localization("添加")] Add = 3, [Localization("删除")] Delete = 4, [Localization("修改")] Edit = 5, [Localization("测试")] Test = 6, [Localization("异常")] Exception = 7 }
public class Log { public int Id { get; set; } public UserModel User { get; set; } [JsonConverter(typeof(EnumLocalizationConverter))] public LogType Type { get; set; } public Guid UId { get; set; } public string Summary { get; set; } public string Clientip { get; set; } public string ServerName { get; set; } public DateTime CreateDT { get; set; } }
