.NET下 JSON 的一些常用操作

1.JSON的序列化和反序列化

首先要先添加引用：

代码如下

 

[csharp] view plain copy print ?

1. using System;  
2. using System.Collections.Generic;  
3. using System.Linq;  
4. using System.Text;  
5. using Newtonsoft.Json;  
6.   
7. namespace PlayJSON  
8. {  
9.     class Program  
10.     {  
11.         static void Main(string[] args)  
12.         {  
13.             List<StuInfo> list = new List<StuInfo>() { new StuInfo{StuName="张三",StuSex="男",StuAge=11},  
14.                                                        new StuInfo{StuName="李四",StuSex="男",StuAge=32},  
15.                                                        new StuInfo{StuName="王翠花",StuSex="女",StuAge=64}  
16.                                                       };  
17.             string jsonStr = JavaScriptConvert.SerializeObject(list);  //将对象转换成json存储   
18.             Console.WriteLine("JSON字符串"+jsonStr);  
19.             Console.ReadLine();  
20.   
21.             List<StuInfo> newList = new List<StuInfo>();  
22.   
23.            newList = (List<StuInfo>)JavaScriptConvert.DeserializeObject(jsonStr,typeof(List<StuInfo>));   //反序列化   
24.   
25.             //StuInfo s = new StuInfo() { StuName = "阿龙", StuSex = "男", StuAge = 33 };   
26.   
27.             //string sigleJSON = JavaScriptConvert.SerializeObject(s);   
28.   
29.            //StuInfo newS = (StuInfo)JavaScriptConvert.DeserializeObject(sigleJSON);   
30.            //Console.WriteLine("姓名：" + newS.StuName + "---性别：" + newS.StuSex + "--年龄：" + newS.StuAge + "\n\n");   
31.   
32.   
33.            foreach (StuInfo item in newList)  
34.            {  
35.                Console.WriteLine("姓名：" + item.StuName + "---性别：" + item.StuSex + "--年龄：" + item.StuAge + "\n\n");  
36.            }  
37.             Console.ReadLine();  
38.         }  
39.     }  
40.     public class StuInfo   
41.     {  
42.         public string StuName { set; get; }  
43.         public string StuSex { set; get; }  
44.         public int StuAge { set; get; }  
45.     }  
46. }  

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

namespace PlayJSON
{
    class Program
    {
        static void Main(string[] args)
        {
            List<StuInfo> list = new List<StuInfo>() { new StuInfo{StuName="张三",StuSex="男",StuAge=11},
                                                       new StuInfo{StuName="李四",StuSex="男",StuAge=32},
                                                       new StuInfo{StuName="王翠花",StuSex="女",StuAge=64}
                                                      };
            string jsonStr = JavaScriptConvert.SerializeObject(list);  //将对象转换成json存储
            Console.WriteLine("JSON字符串"+jsonStr);
            Console.ReadLine();

            List<StuInfo> newList = new List<StuInfo>();

           newList = (List<StuInfo>)JavaScriptConvert.DeserializeObject(jsonStr,typeof(List<StuInfo>));   //反序列化

            //StuInfo s = new StuInfo() { StuName = "阿龙", StuSex = "男", StuAge = 33 };

            //string sigleJSON = JavaScriptConvert.SerializeObject(s);

           //StuInfo newS = (StuInfo)JavaScriptConvert.DeserializeObject(sigleJSON);
           //Console.WriteLine("姓名：" + newS.StuName + "---性别：" + newS.StuSex + "--年龄：" + newS.StuAge + "\n\n");


           foreach (StuInfo item in newList)
           {
               Console.WriteLine("姓名：" + item.StuName + "---性别：" + item.StuSex + "--年龄：" + item.StuAge + "\n\n");
           }
            Console.ReadLine();
        }
    }
    public class StuInfo 
    {
        public string StuName { set; get; }
        public string StuSex { set; get; }
        public int StuAge { set; get; }
    }
}

 

2.在web中

首先添加一个一般处理文件 Handler1.ashx：用来返回一个json

 

[csharp] view plain copy print ?

1. /// <summary>   
2.     /// Handler1 的摘要说明   
3.     /// </summary>   
4.     public class Handler1 : IHttpHandler  
5.     {  
6.   
7.         public void ProcessRequest(HttpContext context)  
8.         {  
9.             context.Response.ContentType = "application/json";  
10.   
11.             List<StuInfo> list = new List<StuInfo>() { new StuInfo{StuName="张三",StuSex="男",StuAge=11},  
12.                                                        new StuInfo{StuName="李四",StuSex="男",StuAge=32},  
13.                                                        new StuInfo{StuName="王翠花",StuSex="女",StuAge=64}  
14.                                                       };  
15.             string jsonStr = JavaScriptConvert.SerializeObject(list);  
16.   
17.             context.Response.Write(jsonStr);  
18.   
19.             context.Response.End();  
20.         }  
21.   
22.         public bool IsReusable  
23.         {  
24.             get  
25.             {  
26.                 return false;  
27.             }  
28.         }  
29.     }  
30.     public class StuInfo  
31.     {  
32.         public string StuName { set; get; }  
33.         public string StuSex { set; get; }  
34.         public int StuAge { set; get; }  
35.     }  

/// <summary>
    /// Handler1 的摘要说明
    /// </summary>
    public class Handler1 : IHttpHandler
    {

        public void ProcessRequest(HttpContext context)
        {
            context.Response.ContentType = "application/json";

            List<StuInfo> list = new List<StuInfo>() { new StuInfo{StuName="张三",StuSex="男",StuAge=11},
                                                       new StuInfo{StuName="李四",StuSex="男",StuAge=32},
                                                       new StuInfo{StuName="王翠花",StuSex="女",StuAge=64}
                                                      };
            string jsonStr = JavaScriptConvert.SerializeObject(list);

            context.Response.Write(jsonStr);

            context.Response.End();
        }

        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }
    public class StuInfo
    {
        public string StuName { set; get; }
        public string StuSex { set; get; }
        public int StuAge { set; get; }
    }

前台页面上的调用：这里采用jquery 的ajax请求

 

 

[csharp] view plain copy print ?

1. <head runat="server">  
2.     <title>JSON</title>  
3.     <script src="Scripts/jquery-1.4.1.min.js" type="text/javascript"></script>  
4.     <script type="text/javascript">  
5.         $(function () {  
6.             $("#btnOK").click(function () {  
7.                 $.ajax({  
8.                     type: "JSON",  
9.                     url: "Handler1.ashx",  
10.                     data: null,  
11.                     success: function (msg) {  
12.                         var con="";  
13.                         for (var i = 0; i < msg.length; i++) {  
14.                             con += "姓名：" + msg[i].StuName + "--性别：" + msg[i].StuSex + "--" + "--年龄：" + msg[i].StuAge+"<br/>";  
15.                         }  
16.   
17.                         $("#divContent").html("长度：" + msg.length + "--具体内容：<br/>" + con);  
18.                     }  
19.                 });  
20.             });  
21.         });  
22.     </script>  
23. </head>  
24. <body>  
25.     <form id="form1" runat="server">  
26.     <div>  
27.     <input type="button" id="btnOK" value="点我获得JSON数据" />  
28.     <div id="divContent"></div>  
29.     </div>  
30.     </form>  
31. </body>  

<head runat="server">
    <title>JSON</title>
    <script src="Scripts/jquery-1.4.1.min.js" type="text/javascript"></script>
    <script type="text/javascript">
        $(function () {
            $("#btnOK").click(function () {
                $.ajax({
                    type: "JSON",
                    url: "Handler1.ashx",
                    data: null,
                    success: function (msg) {
                        var con="";
                        for (var i = 0; i < msg.length; i++) {
                            con += "姓名：" + msg[i].StuName + "--性别：" + msg[i].StuSex + "--" + "--年龄：" + msg[i].StuAge+"<br/>";
                        }

                        $("#divContent").html("长度：" + msg.length + "--具体内容：<br/>" + con);
                    }
                });
            });
        });
    </script>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    <input type="button" id="btnOK" value="点我获得JSON数据" />
    <div id="divContent"></div>
    </div>
    </form>
</body>

 

现在经常会用到json,因此经常会需要对其进行序列化和反序列化。，.NET Framewok 3.5也提供了JSON对象序列化和反序列化的类，这就是System.Runtime.Serialization.Json 命名空间下的 DataContractJsonSerializer 类。利用这个类，可以实现JSON对象的序列化和反序列化。

现在我提供一个类JSON对象序列化和反序列化的类供参考用：

[csharp] view plain copy print ?

1. /// <summary>   
2.     /// JSON帮助类。用于将对象转换为Json格式的字符串，或者将Json的字符串转化为对象。   
3.     /// </summary>   
4.     public static class JsonHelper  
5.     {  
6.         /// <summary>   
7.         /// 将对象转化为Json字符串    
8.         /// </summary>   
9.         /// <typeparam name="T">源类型</typeparam>   
10.         /// <param name="obj">源类型实例</param>   
11.         /// <returns>Json字符串</returns>   
12.         public static string GetJsonFromObj<T>(T obj)  
13.         {  
14.             DataContractJsonSerializer jsonSerializer = new DataContractJsonSerializer(obj.GetType());  
15.             using (MemoryStream ms = new MemoryStream())  
16.             {  
17.                 jsonSerializer.WriteObject(ms, obj);  
18.                 return Encoding.UTF8.GetString(ms.ToArray());  
19.             }  
20.         }  
21.   
22.         /// <summary>   
23.         /// 将Json字符串转化为对象   
24.         /// </summary>   
25.         /// <typeparam name="T">目标类型</typeparam>   
26.         /// <param name="strJson">Json字符串</param>   
27.         /// <returns>目标类型的一个实例</returns>   
28.         public static T GetObjFromJson<T>(string strJson)  
29.         {  
30.             T obj = Activator.CreateInstance<T>();  
31.             using (MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(strJson)))  
32.             {  
33.                 DataContractJsonSerializer jsonSerializer = new DataContractJsonSerializer(obj.GetType());  
34.                 return (T)jsonSerializer.ReadObject(ms);  
35.             }  
36.         }  
37.   
38.         /// <summary>   
39.         /// 将DataTable转换为JSON字符串   
40.         /// </summary>   
41.         /// <param name="dt">数据表</param>   
42.         /// <returns>JSON字符串</returns>   
43.         public static string GetJsonFromDataTable(DataTable dt)  
44.         {  
45.             StringBuilder JsonString = new StringBuilder();  
46.             if (dt != null && dt.Rows.Count > 0)  
47.             {  
48.                 JsonString.Append("{ ");  
49.                 JsonString.Append("\"TableInfo\":[ ");  
50.                 for (int i = 0; i < dt.Rows.Count; i++)  
51.                 {  
52.                     JsonString.Append("{ ");  
53.                     for (int j = 0; j < dt.Columns.Count; j++)  
54.                     {  
55.                         if (j < dt.Columns.Count - 1)  
56.                         {  
57.                             JsonString.Append("\"" + dt.Columns[j].ColumnName.ToString() + "\":" + "\"" + dt.Rows[i][j].ToString() + "\",");  
58.                         }  
59.                         else if (j == dt.Columns.Count - 1)  
60.                         {  
61.                             JsonString.Append("\"" + dt.Columns[j].ColumnName.ToString() + "\":" + "\"" + dt.Rows[i][j].ToString() + "\"");  
62.                         }  
63.                     }  
64.                     if (i == dt.Rows.Count - 1)  
65.                     {  
66.                         JsonString.Append("} ");  
67.                     }  
68.                     else  
69.                     {  
70.                         JsonString.Append("}, ");  
71.                     }  
72.                 }  
73.                 JsonString.Append("]}");  
74.                 return JsonString.ToString();  
75.             }  
76.             else  
77.             {  
78.                 return null;  
79.             }  
80.         }  
81.   
82.         /// <summary>    
83.         /// 将对象转化为Json字符串    
84.         /// </summary>    
85.         /// <param name="obj">源对象</param>    
86.         /// <returns>json数据</returns>    
87.         public static string ObjToJson(this object obj)  
88.         {  
89.             JavaScriptSerializer serialize = new JavaScriptSerializer();  
90.             return serialize.Serialize(obj);  
91.         }  
92.   
93.         /// <summary>    
94.         /// 将Json字符串转化为对象   
95.         /// </summary>    
96.         /// <param name="strJson">Json字符串</param>    
97.         /// <returns>目标对象</returns>   
98.         public static T JsonToObj<T>(string strJson)  
99.         {  
100.             JavaScriptSerializer serialize = new JavaScriptSerializer();  
101.             return serialize.Deserialize<T>(strJson);  
102.         }  
103.   
104.         /// <summary>    
105.         /// 将对象转化为Json字符串(控制深度 )   
106.         /// </summary>    
107.         /// <param name="obj">源对象</param>    
108.         /// <param name="recursionDepth">深度</param>    
109.         /// <returns>json数据</returns>    
110.         public static string ObjToJson(this object obj, int recursionDepth)  
111.         {  
112.             JavaScriptSerializer serialize = new JavaScriptSerializer();  
113.             serialize.RecursionLimit = recursionDepth;  
114.             return serialize.Serialize(obj);  
115.         }  
116.   
117.         /// <summary>    
118.         /// 将Json字符串转化为对象(控制深度 )   
119.         /// </summary>    
120.         /// <param name="strJson">Json字符串</param>    
121.         /// <param name="recursionDepth">深度</param>    
122.         /// <returns>目标对象</returns>   
123.         public static T JsonToObj<T>(string strJson, int recursionDepth)  
124.         {  
125.             JavaScriptSerializer serialize = new JavaScriptSerializer();  
126.             serialize.RecursionLimit = recursionDepth;  
127.             return serialize.Deserialize<T>(strJson);  
128.         }  
129.   
130.         /// <summary>    
131.         /// 将DataTable转换为JSON字符串   
132.         /// </summary>    
133.         /// <param name="dt">DataTable</param>    
134.         /// <returns>json数据</returns>    
135.         public static string DataTableToJson(DataTable dt)  
136.         {  
137.             Dictionary<string, object> dic = new Dictionary<string, object>();  
138.   
139.             int index = 0;  
140.             foreach (DataRow dr in dt.Rows)  
141.             {  
142.                 Dictionary<string, object> result = new Dictionary<string, object>();  
143.   
144.                 foreach (DataColumn dc in dt.Columns)  
145.                 {  
146.                     result.Add(dc.ColumnName, dr[dc].ToString());  
147.                 }  
148.                 dic.Add(index.ToString(), result);  
149.                 index++;  
150.             }  
151.             return ObjToJson(dic);  
152.         }  
153.     }  

/// <summary>
    /// JSON帮助类。用于将对象转换为Json格式的字符串，或者将Json的字符串转化为对象。
    /// </summary>
    public static class JsonHelper
    {
        /// <summary>
        /// 将对象转化为Json字符串 
        /// </summary>
        /// <typeparam name="T">源类型</typeparam>
        /// <param name="obj">源类型实例</param>
        /// <returns>Json字符串</returns>
        public static string GetJsonFromObj<T>(T obj)
        {
            DataContractJsonSerializer jsonSerializer = new DataContractJsonSerializer(obj.GetType());
            using (MemoryStream ms = new MemoryStream())
            {
                jsonSerializer.WriteObject(ms, obj);
                return Encoding.UTF8.GetString(ms.ToArray());
            }
        }

        /// <summary>
        /// 将Json字符串转化为对象
        /// </summary>
        /// <typeparam name="T">目标类型</typeparam>
        /// <param name="strJson">Json字符串</param>
        /// <returns>目标类型的一个实例</returns>
        public static T GetObjFromJson<T>(string strJson)
        {
            T obj = Activator.CreateInstance<T>();
            using (MemoryStream ms = new MemoryStream(Encoding.UTF8.GetBytes(strJson)))
            {
                DataContractJsonSerializer jsonSerializer = new DataContractJsonSerializer(obj.GetType());
                return (T)jsonSerializer.ReadObject(ms);
            }
        }

        /// <summary>
        /// 将DataTable转换为JSON字符串
        /// </summary>
        /// <param name="dt">数据表</param>
        /// <returns>JSON字符串</returns>
        public static string GetJsonFromDataTable(DataTable dt)
        {
            StringBuilder JsonString = new StringBuilder();
            if (dt != null && dt.Rows.Count > 0)
            {
                JsonString.Append("{ ");
                JsonString.Append("\"TableInfo\":[ ");
                for (int i = 0; i < dt.Rows.Count; i++)
                {
                    JsonString.Append("{ ");
                    for (int j = 0; j < dt.Columns.Count; j++)
                    {
                        if (j < dt.Columns.Count - 1)
                        {
                            JsonString.Append("\"" + dt.Columns[j].ColumnName.ToString() + "\":" + "\"" + dt.Rows[i][j].ToString() + "\",");
                        }
                        else if (j == dt.Columns.Count - 1)
                        {
                            JsonString.Append("\"" + dt.Columns[j].ColumnName.ToString() + "\":" + "\"" + dt.Rows[i][j].ToString() + "\"");
                        }
                    }
                    if (i == dt.Rows.Count - 1)
                    {
                        JsonString.Append("} ");
                    }
                    else
                    {
                        JsonString.Append("}, ");
                    }
                }
                JsonString.Append("]}");
                return JsonString.ToString();
            }
            else
            {
                return null;
            }
        }

        /// <summary> 
        /// 将对象转化为Json字符串 
        /// </summary> 
        /// <param name="obj">源对象</param> 
        /// <returns>json数据</returns> 
        public static string ObjToJson(this object obj)
        {
            JavaScriptSerializer serialize = new JavaScriptSerializer();
            return serialize.Serialize(obj);
        }

        /// <summary> 
        /// 将Json字符串转化为对象
        /// </summary> 
        /// <param name="strJson">Json字符串</param> 
        /// <returns>目标对象</returns>
        public static T JsonToObj<T>(string strJson)
        {
            JavaScriptSerializer serialize = new JavaScriptSerializer();
            return serialize.Deserialize<T>(strJson);
        }

        /// <summary> 
        /// 将对象转化为Json字符串(控制深度 )
        /// </summary> 
        /// <param name="obj">源对象</param> 
        /// <param name="recursionDepth">深度</param> 
        /// <returns>json数据</returns> 
        public static string ObjToJson(this object obj, int recursionDepth)
        {
            JavaScriptSerializer serialize = new JavaScriptSerializer();
            serialize.RecursionLimit = recursionDepth;
            return serialize.Serialize(obj);
        }

        /// <summary> 
        /// 将Json字符串转化为对象(控制深度 )
        /// </summary> 
        /// <param name="strJson">Json字符串</param> 
        /// <param name="recursionDepth">深度</param> 
        /// <returns>目标对象</returns>
        public static T JsonToObj<T>(string strJson, int recursionDepth)
        {
            JavaScriptSerializer serialize = new JavaScriptSerializer();
            serialize.RecursionLimit = recursionDepth;
            return serialize.Deserialize<T>(strJson);
        }

        /// <summary> 
        /// 将DataTable转换为JSON字符串
        /// </summary> 
        /// <param name="dt">DataTable</param> 
        /// <returns>json数据</returns> 
        public static string DataTableToJson(DataTable dt)
        {
            Dictionary<string, object> dic = new Dictionary<string, object>();

            int index = 0;
            foreach (DataRow dr in dt.Rows)
            {
                Dictionary<string, object> result = new Dictionary<string, object>();

                foreach (DataColumn dc in dt.Columns)
                {
                    result.Add(dc.ColumnName, dr[dc].ToString());
                }
                dic.Add(index.ToString(), result);
                index++;
            }
            return ObjToJson(dic);
        }
    }

 

使用如下：

 

[csharp] view plain copy print ?

1. public partial class WebForm1 : System.Web.UI.Page  
2.     {  
3.         protected void Page_Load(object sender, EventArgs e)  
4.         {  
5.   
6.         }  
7.   
8.         protected void Button1_Click(object sender, EventArgs e)  
9.         {  
10.             //反序列化成对象        
11.             String strJson = "{\"Name\":\"Test123\",\"Url\":\"http://www.126.com/\"}";  
12.             Person p1 = JsonHelper.GetObjFromJson<Person>(strJson);  
13.             Response.Write("<li>" + p1.Name + " " + p1.Url);  
14.             Person p2 = JsonHelper.JsonToObj<Person>(strJson);  
15.             Response.Write("<li>" + p2.Name + " " + p2.Url);  
16.         }  
17.   
18.         protected void Button2_Click(object sender, EventArgs e)  
19.         {  
20.             //对象的序列化    
21.             String JSONString = string.Empty;  
22.             Person p1 = new Person();  
23.             p1.Name = "Test123'\"\n\r\t";  
24.             p1.Url = "http://www.126.com/";  
25.             JSONString = JsonHelper.GetJsonFromObj<Person>(p1);  
26.             Response.Write("<li>" + JSONString);  
27.             JSONString = JsonHelper.ObjToJson(p1);  
28.             Response.Write("<li>" + JSONString);  
29.         }  
30.     }  
31.   
32.     /// <summary>    
33.     /// 类对象需要标记为DataContractAttribute    
34.     /// </summary>    
35.     [DataContractAttribute]  
36.     class Person  
37.     {  
38.         //成员需要标记为 DataMember    
39.         [DataMember]  
40.         public string Name { set; get; }  
41.         [DataMember]  
42.         public string Url { set; get; }  
43.     }  

public partial class WebForm1 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {

        }

        protected void Button1_Click(object sender, EventArgs e)
        {
            //反序列化成对象     
            String strJson = "{\"Name\":\"Test123\",\"Url\":\"http://www.126.com/\"}";
            Person p1 = JsonHelper.GetObjFromJson<Person>(strJson);
            Response.Write("<li>" + p1.Name + " " + p1.Url);
            Person p2 = JsonHelper.JsonToObj<Person>(strJson);
            Response.Write("<li>" + p2.Name + " " + p2.Url);
        }

        protected void Button2_Click(object sender, EventArgs e)
        {
            //对象的序列化 
            String JSONString = string.Empty;
            Person p1 = new Person();
            p1.Name = "Test123'\"\n\r\t";
            p1.Url = "http://www.126.com/";
            JSONString = JsonHelper.GetJsonFromObj<Person>(p1);
            Response.Write("<li>" + JSONString);
            JSONString = JsonHelper.ObjToJson(p1);
            Response.Write("<li>" + JSONString);
        }
    }

    /// <summary> 
    /// 类对象需要标记为DataContractAttribute 
    /// </summary> 
    [DataContractAttribute]
    class Person
    {
        //成员需要标记为 DataMember 
        [DataMember]
        public string Name { set; get; }
        [DataMember]
        public string Url { set; get; }
    }

 

 

Json.NET json字符串反序列化为json对象 

 

 

 

如何将一个字符串转换为JSON对象呢？如果先创建一个类的话，那就太累了。

var o = new
{
   a = 1,
   b = "Hello, World!",
   c = new[] { 1, 2, 3 },
   d = new Dictionary<string, int> { { "x", 1 }, { "y", 2 } }
};

var json = JsonConvert.SerializeObject(o);

现在json是一个字符串。

第一种做法（匿名类）：

var anonymous = new { a = 0, b = String.Empty, c = new int[0], d = new Dictionary<string, int>() };
var o2 = JsonConvert.DeserializeAnonymousType(json, anonymous);

Console.WriteLine(o2.b);
Console.WriteLine(o2.c[1]);

第二种做法（匿名类）：

var o3 = JsonConvert.DeserializeAnonymousType(json, new { c = new int[0], d = new Dictionary<string, int>() });

Console.WriteLine(o3.d["y"]);

DeserializeAnonymousType 只是借助这个匿名对象参数(anonymous) 反射类型而已，也就是说它和反序列化结果并非同一个对象。正如 o3 那样，我们也可以只提取局部信息。

 

第三种做法（索引器）：

实际上，我们也可以直接反序列化为 JObject，然后通过索引器直接访问。JObject、JProperty 等都继承自 JToken，它重载了基元类型转换操作符，我们可以直接得到实际结果。
var o2 = JsonConvert.DeserializeObject(json) as JObject;

Console.WriteLine((int)o2["a"]);
Console.WriteLine((string)o2["b"]);
Console.WriteLine(o2["c"].Values().Count());
Console.WriteLine((int)o2["d"]["y"]);