此类目的是防治序列化Json字符串时的循环引用问题-------最好解决方案

http://james.newtonking.com/json/help/index.html

using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;

namespace AccpStudentMIS
{
//此类目的是防治序列化Json字符串时的循环引用问题
//此类为Object类的扩展方法，需要引用Newtonsoft.Json.dll类
//使用方法：在Controller中调用 Content(对象.ToJsonString(), "text/html;charset=UTF-8");方法来返回Json
public static class ObjectExtentions
{
public static string ToJsonString(this Object obj)
{

JsonSerializerSettings jsSettings = new JsonSerializerSettings();
jsSettings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore;
return JsonConvert.SerializeObject(obj, jsSettings);
}
}
}

Newtonsoft中的几个妙用

记录Newtonsoft在序列成Json时的两个妙用

JsonSerializerSettings js = new JsonSerializerSettings();

//1、属性为Null时不做序列化输出

js.NullValueHandling = NullValueHandling.Ignore;

//2、属性为DateTime时,做指定的格式输出

js.Converters.Add(new IsoDateTimeConverter()
{
DateTimeFormat ="yyyy-MM-dd HH:mm:ss"
});

JsonConvert.SerializeObject(obj, Formatting.None, js);

//3、设定某个属性不做json序列化输出（在属性头加[JsonIgnore]）

[JsonIgnore]
public string Srl
{
get;
set;
}

/// <summary>
/// 转化为JSON格式
/// </summary>
/// <param name="obj"></param>
/// <param name="depth">RecursionLimit</param>
/// <returns></returns>
public static string ToJson(this object obj, int maxDepth = 10)
{
JsonSerializerSettings settings = new JsonSerializerSettings();
//settings.MaxDepth = maxDepth;
settings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore;
settings.Converters.Add(new JavaScriptDateTimeConverter());
return JsonConvert.SerializeObject(obj, settings);
}

public static string ToJsonIsoDateTime(this object obj)
{
JsonSerializerSettings settings = new JsonSerializerSettings();
settings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore;
settings.Converters.Add(new IsoDateTimeConverter());
return JsonConvert.SerializeObject(obj, settings);
}

/// <summary>
/// 将JSON反序列化为对象
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="sJason"></param>
/// <returns></returns>
public static T FromJson<T>(this string obj, int maxDepth = 2)
{
JsonSerializerSettings settings = new JsonSerializerSettings();
//settings.MaxDepth = maxDepth;
settings.ReferenceLoopHandling = ReferenceLoopHandling.Ignore;
settings.Converters.Add(new JavaScriptDateTimeConverter());
return JsonConvert.DeserializeObject<T>(obj, settings);
}

/// <summary>
/// 将JSON反序列化为对象
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="sJason"></param>
/// <returns></returns>
public static T FromJsonIsoDateTime<T>(this string obj)
{
return JsonConvert.DeserializeObject<T>(obj, new IsoDateTimeConverter());
}

/// <summary>
/// 转化为JSON格式
/// </summary>
/// <param name="obj"></param>
/// <param name="depth">RecursionLimit</param>
/// <returns></returns>
public static string ToJson(object obj, int maxDepth = 2)
{
return obj.ToJson(maxDepth);
}

/// <summary>
/// 将JSON反序列化为对象
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="sJason"></param>
/// <returns></returns>
public static T FromJson<T>(string obj, int maxDepth = 2)
{
return obj.FromJson<T>(maxDepth);
}