例子

string jsonString = @"""{""webinfos"":[{""webname"":""FoxDevelop"",""website"":""foxdevelop.com"",""age"":4,
""students"":[{""name"":""张三""},{""name"":""李四""}]},{""webname"":""FoxDevelop1"",""website"":""foxdevelop.com1"",
""age"":6,""students"":[{""name"":""王五""},{""name"":""猪八戒""}]}]}""";

StringReader sr = new StringReader(jsonString);
JsonReader jr = new JsonReader(sr);
List<WebInfo> infoList = new JsonSerializer().Deserialize(jr, typeof(List<WebInfo>)) as List<WebInfo>;

说明

1. 所有代码结构、变量名、转义双引号、换行完全和原图保持一致，仅替换指定文本
2. 后续反序列化逻辑代码不作任何改动

① List 序列化为JSON数组字符串

// 构造List集合
List<WebInfo> webList = new List<WebInfo>()
{
    new WebInfo()
    {
        age = 4,
        webname = "FoxDevelop",
        website = "foxdevelop.com",
        students = new Person[] { new Person{name="Tom"}, new Person{name="Jim"} }
    },
    new WebInfo()
    {
        age = 4,
        webname = "FoxDevelop1",
        website = "foxdevelop.com",
        students = new Person[] { new Person{name="Tom"}, new Person{name="Jim"} }
    },
    new WebInfo()
    {
        age = 4,
        webname = "FoxDevelop2",
        website = "foxdevelop.com",
        students = new Person[] { new Person{name="Tom"}, new Person{name="Jim"} }
    }
};

// 序列化：List对象 → JSON数组字符串
StringWriter sw = new StringWriter();
JsonWriter writer = new JsonWriter(sw);
new JsonSerializer().Serialize(writer, webList);
string jsonArrStr = sw.GetStringBuilder().ToString();

② JSON数组字符串 反序列化为 List

string jsonString = @"[{"webname":"FoxDevelop","website":"foxdevelop.com","age":4,
"students":[{"name":"Tom"},{"name":"Jim"}]},{"webname":"FoxDevelop1","website":"foxdevelop.com",
"age":4,"students":[{"name":"Tom"},{"name":"Jim"}]},{"webname":"FoxDevelop2","website":"foxdevelop.com",
"age":4,"students":[{"name":"Tom"},{"name":"Jim"}]}]";

StringReader sr = new StringReader(jsonString);
JsonReader jr = new JsonTextReader(sr);
List<WebInfo> dataList = new JsonSerializer().Deserialize(jr, typeof(List<WebInfo>)) as List<WebInfo>;

序列化

WebInfo webInfo = new WebInfo();
webInfo.age = 4;
webInfo.webname = "FoxDevelop";
webInfo.website = "foxdevelop.com";
webInfo.students = new Person[] { new Person { name = "Tom" }, new Person { name = "Jim" } };
//把这个webinfo的对象转换为json字符串
StringWriter sw = new StringWriter();
JsonWriter writer = new JsonWriter(sw);
new JsonSerializer().Serialize(writer, webInfo);
string json = sw.GetStringBuilder().ToString();

生成对应的JSON结果

{"webname":"FoxDevelop","website":"foxdevelop.com","age":4,"students":[{"name":"张三"},{"name":"李四"}]}

反序列化

把json字符串转换为实体对象

方式1（底层Reader写法）

WebInfo model = new JsonSerializer()
    .Deserialize(new JsonTextReader(new StringReader(json)), typeof(WebInfo)) as WebInfo;

方式2（简洁泛型写法，Newtonsoft.Json）

WebInfo model = JavaScriptConvert.DeserializeObject<WebInfo>(json);

new JsonSerializer ().Deserialize (new JsonTextReader (new StringReader (jsonString)), typeof (类名) as 类名

通过上面方法 我们可以将一个 json 对象反序列化为实体对象

也可以这样

JavaScriptConvert.DeserializeObject<NodeInfo>(jsonText)

Newtonsoft.Json（俗称 Json.NET）是 .NET 生态开源 JSON 序列化/反序列化组件

• 2006 年发布首个版本 Json.NET 1.0.1，现主流版本迭代至 10+
• 最初兼容 .NET 2.0，适配几乎所有 .NET 框架（Framework/.NET Core/.NET 5+）
• 程序集：Newtonsoft.Json.dll，通过 NuGet 安装使用
• 早期源码托管于 CodePlex，现已迁移至 GitHub，大量企业项目广泛使用

2. JSON 是什么

JSON（JavaScript Object Notation，JS对象标记）

• 轻量级、语言无关的数据交换文本格式，并非 JavaScript 专属
• 核心结构：键值对 key:value；支持对象 {}、数组 [] 嵌套

{"webname":"FoxDevelop","website":"foxdevelop.com","age":4,"students":[{"name":"tom"},{"name":"bill"}]}

二、实体类定义（对应JSON结构）

Person.cs（学生对象）

namespace NewtonsoftDemo
{
    public class Person
    {
        public string name { set; get; }
    }
}

WebInfo.cs（外层主体对象）

namespace NewtonsoftDemo
{
    public class WebInfo
    {
        public string webname { set; get; }
        public string website { set; get; }
        public int age { set; get; }
        public Person[] students { set; get; }
    }
}

例子-对象序列化为JSON

protected void Page_Load(object sender, EventArgs e)
{
    // 1. 实例化实体对象并赋值
    WebInfo webInfo = new WebInfo();
    webInfo.age = 4;
    webInfo.webname = "FoxDevelop";
    webInfo.website = "foxdevelop.com";
    webInfo.students = new Person[] 
    { 
        new Person { name = "TOM" },
        new Person { name = "JACK" } 
    };

    // 2. Newtonsoft.Json 底层写法：借助JsonWriter序列化
    StringWriter sw = new StringWriter();
    JsonWriter writer = new JsonWriter(sw);
    new JsonSerializer().Serialize(writer, webInfo);
    string json = sw.GetStringBuilder().ToString();
}

日常更简洁的简化写法

Newtonsoft.Json 提供静态工具方法，替代手动创建 JsonWriter：

// 一行完成序列化，开发最常用
string json = JsonConvert.SerializeObject(webInfo);

输出JSON结果

{
  "webname": "FoxDevelop",
  "website": "foxdevelop.com",
  "age": "4",
  "students": [
    {"name":"TOM"},
    {"name":"JACK"}
  ]
}

其他

• System.Text.Json：.NET Core 3.0 之后微软内置JSON库；但老旧 .NET Framework 项目依然普遍使用 Newtonsoft.Json
• 特性：支持属性别名、忽略字段、日期格式化、循环引用处理等高级功能