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标题: 常见的解析JSON方法 [打印本页]

作者: Xiaoxue 时间: 2016-10-27 16:23
标题: 常见的解析JSON方法
对比.NET下几种常见的解析JSON方法[td]

主要类	命名空间	限制	内建LINQ支持
DataContractJsonSerializer	System.Runtime.Serialization.Json	通用	否
JavaScriptSerializer	System.Web.Script.Serialization	只能在Web环境使用	否
JsonArray、JsonObject、JsonValue	System.Json	只能在Silverlight中使用	是
JsonConvert、JArray、JObject、JValue、JProperty	Newtonsoft.Json	通用	是

准备数据
实体类：

[DataContract]
public class Person
{
      [DataMember(Order = 0, IsRequired = true)]
      public string Name { get; set; }

      [DataMember(Order = 1)]
      public int Age { get; set; }

      [DataMember(Order = 2)]
      public bool Alive { get; set; }

      [DataMember(Order = 3)]
      public string[] FavoriteFilms { get; set; }

      [DataMember(Order = 4)]
      public Person Child { get; set; }
}
定义：

Action<object> log = o => Console.WriteLine(o);
Func<int, int, int> add = (x, y) => x + y;

var p1 = new Person {
Age = 12,
Alive = true,
Name = "lj",
FavoriteFilms = new[] { "Up", "Avatar" }
};
var p2 = new Person() { Age = 28, Name = "cy", Child = p1 };

使用DataContractJsonSerializer
帮助类：

  // using System.Runtime.Serialization.Json;

/// <summary>
/// 解析JSON，仿Javascript风格
/// </summary>
public static class JSON
{

      public static T parse<T>(string jsonString)
      {
         using (var ms = new MemoryStream(Encoding.UTF8.GetBytes(jsonString)))
         {
            return (T)new DataContractJsonSerializer(typeof(T)).ReadObject(ms);
         }
      }

      public static string stringify(object jsonObject)
      {
         using (var ms = new MemoryStream())
         {
            new DataContractJsonSerializer(jsonObject.GetType()).WriteObject(ms, jsonObject);
            return Encoding.UTF8.GetString(ms.ToArray());
         }
      }
}
用法：

// 序列化
var jsonString = JSON.stringify(new[] { p1, p2 });
log(jsonString == JSON.stringify(new List<Person>() { p1, p2 })); //true
log(jsonString);
// 反序列化，泛型集合
JSON.parse<List<Person>>(jsonString);
// 数组转换
JSON.parse<Person[]>(jsonString);
输出：

[{"Name":"lj","Age":12,"Alive":true,"FavoriteFilms":["Up","Avatar"],"Child":null
},{"Name":"cy","Age":28,"Alive":false,"FavoriteFilms":null,"Child":{"Name":"lj",
"Age":12,"Alive":true,"FavoriteFilms":["Up","Avatar"],"Child":null}}]
使用JavaScriptSerializer
  // using System.Web.Script.Serialization;

var jser = new JavaScriptSerializer();
var json = jser.Serialize(new List<Person>() { p1, p2 });
var persons = jser.Deserialize<List<Person>>(json);
使用Silverlight
  // using System.Json

var css = "{ \"#header\" : {background:\"red\"}, layout : [5,4,1],color:\"cyan\" }";

var style = JsonObject.Parse(css) as JsonObject;

(
from s in style
where s.Key == "color"
select (string)s.Value
).First().ToString();
// "cyan"

// 更多操作
style["layout"][0] = 22;

var hd = style["#header"];
style["body>div+p"] = hd;
style.Remove("#header");

var bd = new JsonObject();
bd["border"] = "1px solid cyan";
style["body>div+p"]["#meta"] = bd;
style.ToString();
// {"layout":[22,4,1],"color":"cyan","body>div+p":{"background":"red","#meta":{"border":"1px solid cyan"}}}
使用JSON.NET
  // using Newtonsoft.Json;

var json = JsonConvert.SerializeObject(new[] { p1, p2 });
var persons = JsonConvert.DeserializeObject<List<Person>>(json);
var ja = JArray.Parse(jsonString);
log(ja);       //注意，格式化过的输出
输出：

[
  {
"Name": "lj",
"Age": 12,
"Alive": true,
"FavoriteFilms": [
   "Up",
   "Avatar"
],
"Child": null
  },
  {
"Name": "cy",
"Age": 28,
"Alive": false,
"FavoriteFilms": null,
"Child": {
   "Name": "lj",
   "Age": 12,
   "Alive": true,
   "FavoriteFilms": [
      "Up",
      "Avatar"
   ],
   "Child": null
}
  }
]
LINQ：

var ageCount = ja.Select(j => (int)j["Age"]).Aggregate(add);
var q = from j in ja
         where !j["Name"].Value<string>().Equals("lj")
         select (int)j["Age"];

log(q.Aggregate(add) == ageCount);  //false
其他：

  // 与Linq to XML 相似的嵌套构造函数：
var jo = new JObject(
                  new JProperty("age", persons.Select( p => p.Age)),
                  new JProperty("funny", true),
                  new JProperty("array", new JArray(new[] { 2, 4, 1 }))
                  );
log(jo);

// JObject 操作
var css = "{ \"#header\" : {background:\"red\"}, layout : [5,4,1] }";
var style = JObject.Parse(css);

var bd = new JObject();
bd["color"] = "1px solid cyan";

style["border"] = bd;

var hd = style["#header"];
style["body>div+p"] = hd;

hd.Parent.Remove();

style["layout"][0] = 22;
log(style);
输出：

{
   "age": [
      12,
      28
   ],
   "funny": true,
   "array": [
      2,
      4,
      1
   ]
}
{
   "layout": [
      22,
      4,
      1
   ],
   "border": {
      "color": "1px solid cyan"
   },
   "body>div+p": {
      "background": "red"
   }
}

作者: admin 时间: 2016-10-27 16:32
http://www.cnblogs.com/ambar/arc ... son-via-csharp.html

作者: admin 时间: 2016-10-27 16:47
NewtonSoft.Json的安装：
http://jingyan.baidu.com/article/6fb756ecd2b051241858fbef.html

作者: admin 时间: 2016-10-27 20:47
http://www.newtonsoft.com/json

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