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
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)
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 }
方法二：DataContractJsonSerializer
使用这种 需要引用 System.Runtime.Serialization.dll
1 class JsonDataContractJsonSerializer
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)
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 }
方法三：JavaScriptSerializer
需要引用：System.Web.Extensions.dll
1 public static class JsonJavaScriptSerializer
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)
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 }
程序测试：
新建一个测试对象类Student.cs
1 public enum Sex
3 男=0,
4 女=1
6 [Serializable()]
7 class Student
9 private string _name;
11 public string Name
12 {
13 get { return _name; }
14 set { _name = value; }
15 }
17 private int _age;
19 public int Age
20 {
21 get { return _age; }
22 set { _age = value; }
23 }
25 private Sex _sex = Sex.男;
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 }
1 static void Main(string[] args)
3 Student st = new Student("笨男孩",22,Sex.男);
5 Console.WriteLine("============方法一============================================");
6 //方法一
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);
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);
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);
35 Console.ReadKey();
程序运行结果：
运行结果：
功能对比：
性能对比：
综上所述，一般采用Json.NET方法一比较好！
JavaScriptSerializer 类介绍 https://msdn.microsoft.com/zh-cn/library/system.web.script.serialization.javascriptserializer(v=vs.110).aspx
DataContractJsonSerializer类介绍 https://msdn.microsoft.com/zh-cn/library/system.runtime.serialization.json.datacontractjsonserializer(v=vs.110).aspx
https://blog.csdn.net/testcs_dn/article/details/78150046?locationNum=6&fps=1
