EF 序列化实体为Json时的循环引用问题(不用自己写实体,不用匿名类型,不用EF的上下文属性)

自己写实体可以完美解决这个问题。(支持时间格式自定义)

用匿名类型也可以。

设置上下文方法如下：

(jz为数据库上下文对象)

jz.Configuration.ProxyCreationEnabled = false;
jz.Configuration.LazyLoadingEnabled = false;

不用这个的原因是Virtual属性也会生成。（只是占个位，[]里面没内容，但看着不爽）

我采用的方法是过滤掉Virtual属性的方法：

一个基于Json.net的类

using Newtonsoft.Json; using Newtonsoft.Json.Converters; using Newtonsoft.Json.Serialization; using System; using System.Collections.Generic; using System.Linq; using System.Reflection; using System.Web; namespace AceepSystem.Models.Help {  public class JsonForEF : DefaultContractResolver {  string[] props = null;  bool retain; 

/// <summary><br>        /// 构造函数<br>        /// </summary><br>        /// <param name="props">传入的属性数组</param><br>        /// <param name="retain">true:表示props是需要保留的字段  false：表示props是要排除的字段</param><br>        public JsonForEF(string[] props, bool retain = true)<br>        {<br>            //指定要序列化属性的清单<br>            this.props = props;<br><br>            this.retain = retain;<br>        }<br><br>        protected override IList<JsonProperty> CreateProperties(Type type,<br><br>        MemberSerialization memberSerialization)<br>        {<br>            IList<JsonProperty> list =<br>            base.CreateProperties(type, memberSerialization);<br>            //只保留清单有列出的属性<br>            return list.Where(p =><br>            {<br>                if (retain)<br>                {<br>                    return props.Contains(p.PropertyName);<br>                }<br>                else<br>                {<br>                    return !props.Contains(p.PropertyName);<br>                }<br>            }).ToList();<br>        }<br>        public static string[] GetVirtualList<T>()<br>        {<br>            var stringType = typeof(T);<br>            var props = stringType.GetProperties();<br>            List<string> test = new List<string>();<br>            foreach (var prop in props)<br>            {<br>                if (prop.GetAccessors()[0].IsVirtual)<br>                {<br>                    test.Add(prop.Name);<br>                }<br>            }<br>            return test.ToArray();<br>        }<br>        public static JsonSerializerSettings GetJsonConfig<T>()<br>        {<br><br>            JsonSerializerSettings jsetting = new JsonSerializerSettings();//过滤掉ef中的导航属性,无残留...<br>            jsetting.ContractResolver = new JsonForEF(<br>            JsonForEF.GetVirtualList<T>()//泛型方法传入当前要序列化的类型<br>            , false);//false为要排除的属性,true为要保留的属性(第一个参数为string[])<br>            jsetting.Converters.Add(new MyDateTimeConvertor());<br>            return jsetting;<br>        }<br>        public class MyDateTimeConvertor : DateTimeConverterBase<br>        {<br>            public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)<br>            {<br>                return DateTime.Parse(reader.Value.ToString());<br>            }<br><br>            public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)<br>            {<br>                writer.WriteValue(((DateTime)value).ToString("yyyy/MM/dd HH:mm"));<br>            }<br>        }<br>    }<br>}

和一个对PropertyInfo的扩展方法

using System; using System.Collections.Generic; using System.Linq; using System.Reflection; using System.Web; namespace AceepSystem.Models.Help {  public static class Virtual_Help {  public static bool? IsVirtual(this PropertyInfo self) {  if (self == null)  throw new ArgumentNullException("self");  bool? found = null;  foreach (MethodInfo method in self.GetAccessors()) {  if (found.HasValue) {  if (found.Value != method.IsVirtual)  return null; }  else

<br>                {<br>                    found = method.IsVirtual;<br>                }<br>            }<br><br>

return found; } } }

使用方法如下

 string json = JsonConvert.SerializeObject(
               list,
                Formatting.Indented,
                JsonForEF.GetJsonConfig<dic_attribution>()
                );//转C#对象为Json数据