C# 对象与JSON字符串互相转换的三种方式

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         ///  4         /// 把对象转换为JSON字符串 5         /// 
 6         /// 对象 7         /// 
      
       JSON字符串
       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         /// 17         /// 把Json文本转为实体18         /// 
19         /// 
      20         /// 21         /// 
      22         public static T FromJSON
      
       (this string input)23         {24             try25             {26                 return JsonConvert.DeserializeObject
       
        (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         ///  4         /// 内存对象转换为json字符串 5         /// 
 6         ///  7         /// 
       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        /// 19        /// Json字符串转内存对象20        /// 
21        /// 22        /// 23        /// 
      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         ///  4         /// 内存对象转换为json字符串 5         /// 
 6         ///  7         /// 
       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         /// 16         /// Json字符串转内存对象17         /// 
18         /// 19         /// 20         /// 
      21         public static T FromJSON
      
       (string jsonString)22         {23             JavaScriptSerializer json = new JavaScriptSerializer();24             return json.Deserialize
       
        (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 Name12         {13             get { return _name; }14             set { _name = value; }15         }16 17         private int _age;18 19         public int Age20         {21             get { return _age; }22             set { _age = value; }23         }24 25         private Sex _sex = Sex.男;26 27         public Sex Sex28         {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
      
       (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
       
        (jsonStr3);33             Console.WriteLine("姓名:{0} 年龄:{1} 性别:{2}", stobj3.Name, stobj3.Age, stobj3.Sex);34 35             Console.ReadKey();36         }