关于Newtonsoft Json中的集合数据转换

1.嵌套属性的类序列化时会报错.

如:

class Person { public string Name { get; set; } public int Age { get; set; } public string Gender { get; set; } public string Remark { get; set; } public List<Person> Group { get; set; } }

PersonA中有一个List<Person>属性,这将导致序列化时,如果这个属性中有对象自身,那么这个树就会无限循环,所以抛异常.

   

1. 还是以上边的示例,在用JsonConvert.SerializeObject()方法时,如果序列化Person.Group这样的集合属性,其Json文本是如下这样的:

{

"Name": "Park",

"Age": 52,

"Gender": "male",

"Group": [

{

"Name": "Jack",

"Age": 32,

"Gender": "male"

},

{

"Name": "Lily",

"Age": 23,

"Gender": "female"

},

{

"Name": "Ted",

"Age": 13,

"Gender": "male",

"Remark": "his is child"

}

]

}

但如果序列化的是一个List<Person>集合,其文本是如下这样的:

[{"Name":"Jack","Age":32,"Gender":"male","Remark":null},{"Name":"Lily","Age":23,"Gender":"female","Remark":null},{"Name":"Ted","Age":13,"Gender":"male","Remark":"his is child"}]

而我们持续向某一个Json文本中添加Serialized后的JsonText,结果是向下边这样的:

{

"Name": "Jack",

"Age": 32,

"Gender": "male"

}

{

"Name": "Ted",

"Age": 13,

"Gender": "male",

"Remark": "his is child"

}

{

"Name": "Park",

"Age": 52,

"Gender": "male"

}

   

// 注意,这种文件不符合Json文档格式,在Deserialize时会抛出异常:

Newtonsoft.Json.JsonReaderException:"Additional text encountered after finished reading JSON content: {. Path '', line 5, position 1."

  

   

1. 使用JsonConvert.DeserializeObject()方法时,非泛型方法然后再通过as TargetType的方法是不管用的,返回的还是一个null.

Person result1 = JsonConvert.DeserializeObject(jackJson) as Person;

   

附录:全部测试代码放在了下边

using Newtonsoft.Json;

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

   

namespace TestConsoleApp

{

class Program

{

static void Main(string[] args)

{

var jack = new Person() { Name = "Jack", Age = 32, Gender = "male" };

var lily = new Person() { Name = "Lily", Age = 23, Gender = "female" };

var park = new Person() { Name = "Park", Age = 52, Gender = "male" };

var ted = new Person() { Name = "Ted", Age = 13, Gender = "male", Remark = "his is child" };

List<Person> group1 = new List<Person>() { jack, lily, ted };

//park.Group = group1;

//jack.Group = group1;

//lily.Group = group1;

//ted.Group = group1;

   

JsonSerializerSettings jsSetting = new JsonSerializerSettings();

jsSetting.NullValueHandling = NullValueHandling.Ignore;

string jackJson = JsonConvert.SerializeObject(jack, Formatting.Indented, jsSetting);

string tedJson = JsonConvert.SerializeObject(ted, Formatting.Indented, jsSetting);

string groupJson = JsonConvert.SerializeObject(group1);

string parkJson = JsonConvert.SerializeObject(park, Formatting.Indented, jsSetting);

Console.WriteLine(jackJson);

Console.WriteLine(tedJson);

Console.WriteLine(parkJson);

string jsonTextColl = jackJson + tedJson + parkJson;

Person result1 = JsonConvert.DeserializeObject(jackJson) as Person;

Person result2 = JsonConvert.DeserializeObject<Person>(jackJson);

List<Person> result3 = JsonConvert.DeserializeObject<List<Person>>(groupJson);

List<Person> result4 = JsonConvert.DeserializeObject(groupJson) as List<Person>;

List<Person> result5 = JsonConvert.DeserializeObject(jsonTextColl) as List<Person>;

Console.ReadKey();

}

}

   

class Person

{

public string Name { get; set; }

public int Age { get; set; }

public string Gender { get; set; }

public string Remark { get; set; }

//public List<Person> Group { get; set; }

}

}