C# 中对象与JSON字符串相互转换的三种方法

JSON(JavaScript Object Notation, JS 对象标记) 是一种轻量级的数据交换格式。

　　关于内存对象和JSON字符串的相互转换，在实际项目中应比较广泛，经过一番搜索，找到如下三种方法来解决此问题

分别是使用 Newtonsoft.Json.dll、DataContractJsonSerializer、 JavaScriptSerializer。 

方法一： Newtonsoft.Json.dll 

Newtonsoft.Json.dll在.net2.0之后的版本可以支持 我的版本.net framework4.0

添加Newtonsoft.json的引用

对象与json字符串转换类设计

 1     class JsonNewtonsoft
 2     {
 3         /// <summary>
 4         /// 把对象转换为JSON字符串
 5         /// </summary>
 6         /// <param name="o">对象</param>
 7         /// <returns>JSON字符串</returns>
 8         public static string ToJSON(this object o)
 9         {
10             if (o == null)
11             {
12                 return null;
13             }
14             return JsonConvert.SerializeObject(o);
15         }
16         /// <summary>
17         /// 把Json文本转为实体
18         /// </summary>
19         /// <typeparam name="T"></typeparam>
20         /// <param name="input"></param>
21         /// <returns></returns>
22         public static T FromJSON<T>(this string input)
23         {
24             try
25             {
26                 return JsonConvert.DeserializeObject<T>(input);
27             }
28             catch (Exception ex)
29             {
30                 return default(T);
31             }
32         }
33     }  

方法二：DataContractJsonSerializer

 使用这种 需要引用 System.Runtime.Serialization.dll

类设计

 1 class JsonDataContractJsonSerializer
 2     {
 3         /// <summary>
 4         /// 内存对象转换为json字符串
 5         /// </summary>
 6         /// <param name="obj"></param>
 7         /// <returns></returns>
 8         public static string ObjectToJson(object obj)
 9         {
10            DataContractJsonSerializer serializer = new DataContractJsonSerializer(obj.GetType());
11            MemoryStream stream = new MemoryStream();
12            serializer.WriteObject(stream, obj);
13            byte[] dataBytes = new byte[stream.Length];
14            stream.Position = 0;
15            stream.Read(dataBytes, 0, (int)stream.Length);
16            return Encoding.UTF8.GetString(dataBytes);
17         }
18        /// <summary>
19        /// Json字符串转内存对象
20        /// </summary>
21        /// <param name="jsonString"></param>
22        /// <param name="obj"></param>
23        /// <returns></returns>
24         public static object JsonToObject(string jsonString, object obj)
25         {
26            DataContractJsonSerializer serializer = new DataContractJsonSerializer(obj.GetType());
27            MemoryStream mStream = new MemoryStream(Encoding.UTF8.GetBytes(jsonString));
28            return serializer.ReadObject(mStream);
29         }
30     }  

方法三：JavaScriptSerializer

需要引用：System.Web.Extensions.dll

类设计

 1     public static class JsonJavaScriptSerializer
 2     {
 3         /// <summary>
 4         /// 内存对象转换为json字符串
 5         /// </summary>
 6         /// <param name="obj"></param>
 7         /// <returns></returns>
 8         public static string ToJSON(object obj)
 9         {
10             StringBuilder sb = new StringBuilder();
11             JavaScriptSerializer json = new JavaScriptSerializer();
12             json.Serialize(obj, sb);
13             return sb.ToString();
14         }
15         /// <summary>
16         /// Json字符串转内存对象
17         /// </summary>
18         /// <param name="jsonString"></param>
19         /// <param name="obj"></param>
20         /// <returns></returns>
21         public static T FromJSON<T>(string jsonString)
22         {
23             JavaScriptSerializer json = new JavaScriptSerializer();
24             return json.Deserialize<T>(jsonString);
25         }
26 
27     }  

程序测试：

新建一个测试对象类Student.cs

 1     public enum Sex
 2     {
 3         男=0,
 4         女=1
 5     }
 6     [Serializable()]
 7     class Student
 8     {
 9         private string _name;
10 
11         public string Name
12         {
13             get { return _name; }
14             set { _name = value; }
15         }
16 
17         private int _age;
18 
19         public int Age
20         {
21             get { return _age; }
22             set { _age = value; }
23         }
24 
25         private Sex _sex = Sex.男;
26 
27         public Sex Sex
28         {
29             get { return _sex; }
30             set { _sex = value; }
31         }
32         public Student()
33         { }
34         public Student(string name,int age,Sex sex)
35         {
36             this._name = name;
37             this._age = age;
38             this._sex = sex;
39         }
40     }  

测试程序

 1         static void Main(string[] args)
 2         {
 3             Student st = new Student("笨男孩",22,Sex.男);
 4 
 5             Console.WriteLine("============方法一============================================");
 6             //方法一
 7 
 8             Console.WriteLine("方法一对象转Json字符串");
 9             string jsonStr = JsonNewtonsoft.ToJSON(st);
10             Console.WriteLine(jsonStr);
11             Console.WriteLine("方法一Json字符串转对象");
12             Student stobj = (Student)JsonNewtonsoft.FromJSON<Student>(jsonStr);
13             Console.WriteLine("姓名:{0} 年龄:{1} 性别:{2}",stobj.Name,stobj.Age,stobj.Sex);
14 
15 
16             Console.WriteLine("============方法二============================================");
17             //方法二
18             Console.WriteLine("方法二对象转Json字符串");
19             string jsonStr2 = JsonDataContractJsonSerializer.ToJSON(st);
20             Console.WriteLine(jsonStr2);
21             Console.WriteLine("方法二Json字符串转对象");
22             Student stobj2 = (Student)JsonDataContractJsonSerializer.FromJSON(jsonStr2, st);
23             Console.WriteLine("姓名:{0} 年龄:{1} 性别:{2}", stobj2.Name, stobj2.Age, stobj2.Sex);
24 
25 
26             Console.WriteLine("============方法三============================================");
27             //方法二
28             Console.WriteLine("方法三对象转Json字符串");
29             string jsonStr3 = JsonJavaScriptSerializer.ToJSON(st);
30             Console.WriteLine(jsonStr3);
31             Console.WriteLine("方法三Json字符串转对象");
32             Student stobj3 = (Student)JsonJavaScriptSerializer.FromJSON<Student>(jsonStr3);
33             Console.WriteLine("姓名:{0} 年龄:{1} 性别:{2}", stobj3.Name, stobj3.Age, stobj3.Sex);
34 
35             Console.ReadKey();
36         }  

程序运行结果：