等同于 .Net5 中的 JArray.FromObject()？
Equivalent of JArray.FromObject() in .Net5?
我们有一个项目在 .NET 5 中使用 System.Text.Json 而不是 Newtonsoft JObject。使用 Newtonsoft，替换动态 JSON 数据非常容易，例如如下图：
siteDataObject["student"] = JArray.FromObject(studentservice.GetStudents());
当studentservice.GetStudents()为return结构如下
internal class Student {
public int Id { get; set; }
public string Name { get; set; }
public string ContactPhone { get; set; }
public IEnumerable<MedicalRecord> MedicalRecords { get; set; }
}
internal class MedicalRecord {
public int Id { get; set; }
public string Name { get; set; }
public DateTime RecordDate { get; set; }
public IEnumerable<DiseaseLog> DiseaseLogs{ get; set; }
}
internal class DiseaseLog {
public int Id { get; set; }
public string Name { get; set; }
public DateTime LogDate { get; set; }
}
但在System.Text.Json
foreach (var element in doc.RootElement.EnumerateObject()) {
if (element.Name == "student") {
writer.WritePropertyName(element.Name);
}
else {
element.WriteTo(writer);
}
}
我不知道如何将 List<student> 转换成 JSON 数组数据，当学生 class 有很多属性，里面有多个集合。
谁能告诉我如何转换它？
为了澄清，我需要为此提出完整的代码，我有一个动态 json 字符串并想将元素 : students 替换为新记录，代码将是
var dynamicJson = @"{'roomid':1,'roomcode':'Code001','students':[1],'contentdata':'say hello','footerdata':'cookie policy'}";
using MemoryStream stream = new MemoryStream();
using Utf8JsonWriter writer = new Utf8JsonWriter(stream);
using var dynamicDocument = JsonDocument.Parse(dynamicJson);
writer.WriteStartObject();
foreach (var element in dynamicDocument.RootElement.EnumerateObject())
{
if (element.Name == "students")
{
// unknown how to modify the student record into array
}
else
element.WriteTo(writer);
}
writer.WriteEndObject();
stream.Flush();
var modifyJson = Encoding.UTF8.GetString(stream.ToArray());
如果学生元素是字符串，我知道如何修改学生值，但我不知道如何使用简单的代码将其修改为数组。因为学生里面有多个class。
我的预期结果应该是
{
"roomid": 1,
"roomcode": "Code001",
"students": [
{
"id": 1,
"Name": "Wilson",
"ContactPhone": "123-122-3311",
"MedicalRecords": [
{
"id": 101,
"Name ": "Medial record 101011",
"RecordDate": "2021-12-31",
"DiseaseLogs": [
{
"id": 18211,
"Name ": "Patient Log 19292",
"LogDate": "2020-1-31"
},
{
"id": 18212,
"Name ": "Patient Log 2911w",
"LogDate": "2020-3-31"
}
]
}
]
}
],
"contentdata": "say hello",
"footerdata": "cookie policy"
}
我想这就是你想要的（数组或单个嵌套对象）：
var student = new Student()
{
Name = "Student",
ContactPhone = "contact",
Id = 1,
MedicalRecords = new List<MedicalRecord>()
{
new MedicalRecord()
{
Name = "Medical Record 1",
RecordDate= DateTime.Now ,
Id = 1 ,
MedicalRecords = new List<DiseaseLog>()
{
new DiseaseLog(){ Name = "some disease" ,
LogDate = DateTime.Now, Id =1 }
}
}
}
};
var data = System.Text.Json.JsonSerializer.Serialize(student);
Console.WriteLine(data);
var list = new List<Student>();
list.Add(student);
var arrayData = System.Text.Json.JsonSerializer.Serialize(list);
Console.WriteLine(arrayData);
在 .NET 5 中，System.Text.Json 中没有可修改的 JSON 文档对象模型。 JsonDocument is read-only, and System.Text.Json.Nodes 仅在 .NET 6 中引入。因此，反序列化、修改和 re-serialize free-form JSON 在 .NET 5[=57 中的最简单方法=] 是反序列化为一些部分数据模型，将未知值绑定到字典中。
如果您不关心根级别的属性顺序，您可以反序列化为具有 public object students { get; set; } 属性 的模型，并将其余元素绑定到 JsonExtensionData 溢出字典：
public class RootObject
{
public object students { get; set; }
[System.Text.Json.Serialization.JsonExtensionDataAttribute]
public IDictionary<string, object> ExtensionData { get; set; }
}
然后反序列化，修改和re-serialize如下：
var students = new List<Student> { /* Initialize these as required... */ };
var dynamicJson = @"{""roomid"":1,""roomcode"":""Code001"",""students"":[1],""contentdata"":""say hello"",""footerdata"":""cookie policy""}";
var root = JsonSerializer.Deserialize<RootObject>(dynamicJson);
root.students = students;
var modifyJson = JsonSerializer.Serialize(root, new JsonSerializerOptions { PropertyNamingPolicy = JsonNamingPolicy.CamelCase, WriteIndented = true });
结果是
{
"students": [
{
"id": 1,
"name": "Wilson",
"contactPhone": "123-122-3311",
"medicalRecords": [
{
"id": 101,
"name": "Medial record 101011",
"recordDate": "2021-12-31T00:00:00",
"diseaseLogs": [
{
"id": 18211,
"name": "Patient Log 19292",
"logDate": "2020-01-31T00:00:00"
},
{
"id": 18212,
"name": "Patient Log 2911w",
"logDate": "2020-03-31T00:00:00"
}
]
}
]
}
],
"roomid": 1,
"roomcode": "Code001",
"contentdata": "say hello",
"footerdata": "cookie policy"
}
students 属性 必须声明为 object 因为输入 JSON 已经有一个包含单个整数值的数组；将其声明为 public List<Student> students { get; set; } 会在最初加载 JSON.
时导致反序列化
演示 fiddle #1 here.
如果您确实关心根级别的属性顺序，您可以反序列化为 OrderedDictionary（旧的 order-preserving non-generic 字典，可追溯到 .NET Framework 2.0仍然存在并受支持），覆盖 "students" 值，并且 re-serialize:
var students = new List<Student> { /* Initialize these as required... */ };
var dynamicJson = @"{""roomid"":1,""roomcode"":""Code001"",""students"":[1],""contentdata"":""say hello"",""footerdata"":""cookie policy""}";
var root = JsonSerializer.Deserialize<OrderedDictionary>(dynamicJson);
root["students"] = students;
var modifyJson = JsonSerializer.Serialize(root, new JsonSerializerOptions { PropertyNamingPolicy = JsonNamingPolicy.CamelCase, WriteIndented = true });
结果是
{
"roomid": 1,
"roomcode": "Code001",
"students": [
{
"id": 1,
"name": "Wilson",
"contactPhone": "123-122-3311",
"medicalRecords": [
{
"id": 101,
"name": "Medial record 101011",
"recordDate": "2021-12-31T00:00:00",
"diseaseLogs": [
{
"id": 18211,
"name": "Patient Log 19292",
"logDate": "2020-01-31T00:00:00"
},
{
"id": 18212,
"name": "Patient Log 2911w",
"logDate": "2020-03-31T00:00:00"
}
]
}
]
}
],
"contentdata": "say hello",
"footerdata": "cookie policy"
}
演示 fiddle #2 here.
在 .NET 6 中，通过使用 System.Text.Json.Nodes 可编辑的 JSON 文档对象模型，这一切变得更加容易：
var dynamicJson = @"{""roomid"":1,""roomcode"":""Code001"",""students"":[1],""contentdata"":""say hello"",""footerdata"":""cookie policy""}";
var nodes = JsonSerializer.Deserialize<JsonObject>(dynamicJson);
nodes["students"] = JsonSerializer.SerializeToNode(students, new JsonSerializerOptions { PropertyNamingPolicy = JsonNamingPolicy.CamelCase });
var modifyJson = nodes.ToString();
但在 .NET 5 中这是不可能的。演示 fiddle #3 here.
我们有一个项目在 .NET 5 中使用 System.Text.Json 而不是 Newtonsoft JObject。使用 Newtonsoft，替换动态 JSON 数据非常容易，例如如下图：
siteDataObject["student"] = JArray.FromObject(studentservice.GetStudents());
当studentservice.GetStudents()为return结构如下
internal class Student {
public int Id { get; set; }
public string Name { get; set; }
public string ContactPhone { get; set; }
public IEnumerable<MedicalRecord> MedicalRecords { get; set; }
}
internal class MedicalRecord {
public int Id { get; set; }
public string Name { get; set; }
public DateTime RecordDate { get; set; }
public IEnumerable<DiseaseLog> DiseaseLogs{ get; set; }
}
internal class DiseaseLog {
public int Id { get; set; }
public string Name { get; set; }
public DateTime LogDate { get; set; }
}
但在System.Text.Json
foreach (var element in doc.RootElement.EnumerateObject()) {
if (element.Name == "student") {
writer.WritePropertyName(element.Name);
}
else {
element.WriteTo(writer);
}
}
我不知道如何将 List<student> 转换成 JSON 数组数据，当学生 class 有很多属性，里面有多个集合。
谁能告诉我如何转换它？
为了澄清，我需要为此提出完整的代码，我有一个动态 json 字符串并想将元素 : students 替换为新记录，代码将是
var dynamicJson = @"{'roomid':1,'roomcode':'Code001','students':[1],'contentdata':'say hello','footerdata':'cookie policy'}";
using MemoryStream stream = new MemoryStream();
using Utf8JsonWriter writer = new Utf8JsonWriter(stream);
using var dynamicDocument = JsonDocument.Parse(dynamicJson);
writer.WriteStartObject();
foreach (var element in dynamicDocument.RootElement.EnumerateObject())
{
if (element.Name == "students")
{
// unknown how to modify the student record into array
}
else
element.WriteTo(writer);
}
writer.WriteEndObject();
stream.Flush();
var modifyJson = Encoding.UTF8.GetString(stream.ToArray());
如果学生元素是字符串，我知道如何修改学生值，但我不知道如何使用简单的代码将其修改为数组。因为学生里面有多个class。
我的预期结果应该是
{
"roomid": 1,
"roomcode": "Code001",
"students": [
{
"id": 1,
"Name": "Wilson",
"ContactPhone": "123-122-3311",
"MedicalRecords": [
{
"id": 101,
"Name ": "Medial record 101011",
"RecordDate": "2021-12-31",
"DiseaseLogs": [
{
"id": 18211,
"Name ": "Patient Log 19292",
"LogDate": "2020-1-31"
},
{
"id": 18212,
"Name ": "Patient Log 2911w",
"LogDate": "2020-3-31"
}
]
}
]
}
],
"contentdata": "say hello",
"footerdata": "cookie policy"
}
我想这就是你想要的（数组或单个嵌套对象）：
var student = new Student()
{
Name = "Student",
ContactPhone = "contact",
Id = 1,
MedicalRecords = new List<MedicalRecord>()
{
new MedicalRecord()
{
Name = "Medical Record 1",
RecordDate= DateTime.Now ,
Id = 1 ,
MedicalRecords = new List<DiseaseLog>()
{
new DiseaseLog(){ Name = "some disease" ,
LogDate = DateTime.Now, Id =1 }
}
}
}
};
var data = System.Text.Json.JsonSerializer.Serialize(student);
Console.WriteLine(data);
var list = new List<Student>();
list.Add(student);
var arrayData = System.Text.Json.JsonSerializer.Serialize(list);
Console.WriteLine(arrayData);
在 .NET 5 中，System.Text.Json 中没有可修改的 JSON 文档对象模型。 JsonDocument is read-only, and System.Text.Json.Nodes 仅在 .NET 6 中引入。因此，反序列化、修改和 re-serialize free-form JSON 在 .NET 5[=57 中的最简单方法=] 是反序列化为一些部分数据模型，将未知值绑定到字典中。
如果您不关心根级别的属性顺序，您可以反序列化为具有 public object students { get; set; } 属性 的模型，并将其余元素绑定到 JsonExtensionData 溢出字典：
public class RootObject
{
public object students { get; set; }
[System.Text.Json.Serialization.JsonExtensionDataAttribute]
public IDictionary<string, object> ExtensionData { get; set; }
}
然后反序列化，修改和re-serialize如下：
var students = new List<Student> { /* Initialize these as required... */ };
var dynamicJson = @"{""roomid"":1,""roomcode"":""Code001"",""students"":[1],""contentdata"":""say hello"",""footerdata"":""cookie policy""}";
var root = JsonSerializer.Deserialize<RootObject>(dynamicJson);
root.students = students;
var modifyJson = JsonSerializer.Serialize(root, new JsonSerializerOptions { PropertyNamingPolicy = JsonNamingPolicy.CamelCase, WriteIndented = true });
结果是
{
"students": [
{
"id": 1,
"name": "Wilson",
"contactPhone": "123-122-3311",
"medicalRecords": [
{
"id": 101,
"name": "Medial record 101011",
"recordDate": "2021-12-31T00:00:00",
"diseaseLogs": [
{
"id": 18211,
"name": "Patient Log 19292",
"logDate": "2020-01-31T00:00:00"
},
{
"id": 18212,
"name": "Patient Log 2911w",
"logDate": "2020-03-31T00:00:00"
}
]
}
]
}
],
"roomid": 1,
"roomcode": "Code001",
"contentdata": "say hello",
"footerdata": "cookie policy"
}
students 属性 必须声明为 object 因为输入 JSON 已经有一个包含单个整数值的数组；将其声明为 public List<Student> students { get; set; } 会在最初加载 JSON.
演示 fiddle #1 here.
如果您确实关心根级别的属性顺序，您可以反序列化为 OrderedDictionary（旧的 order-preserving non-generic 字典，可追溯到 .NET Framework 2.0仍然存在并受支持），覆盖 "students" 值，并且 re-serialize:
var students = new List<Student> { /* Initialize these as required... */ };
var dynamicJson = @"{""roomid"":1,""roomcode"":""Code001"",""students"":[1],""contentdata"":""say hello"",""footerdata"":""cookie policy""}";
var root = JsonSerializer.Deserialize<OrderedDictionary>(dynamicJson);
root["students"] = students;
var modifyJson = JsonSerializer.Serialize(root, new JsonSerializerOptions { PropertyNamingPolicy = JsonNamingPolicy.CamelCase, WriteIndented = true });
结果是
{
"roomid": 1,
"roomcode": "Code001",
"students": [
{
"id": 1,
"name": "Wilson",
"contactPhone": "123-122-3311",
"medicalRecords": [
{
"id": 101,
"name": "Medial record 101011",
"recordDate": "2021-12-31T00:00:00",
"diseaseLogs": [
{
"id": 18211,
"name": "Patient Log 19292",
"logDate": "2020-01-31T00:00:00"
},
{
"id": 18212,
"name": "Patient Log 2911w",
"logDate": "2020-03-31T00:00:00"
}
]
}
]
}
],
"contentdata": "say hello",
"footerdata": "cookie policy"
}
演示 fiddle #2 here.
在 .NET 6 中，通过使用 System.Text.Json.Nodes 可编辑的 JSON 文档对象模型，这一切变得更加容易：
var dynamicJson = @"{""roomid"":1,""roomcode"":""Code001"",""students"":[1],""contentdata"":""say hello"",""footerdata"":""cookie policy""}";
var nodes = JsonSerializer.Deserialize<JsonObject>(dynamicJson);
nodes["students"] = JsonSerializer.SerializeToNode(students, new JsonSerializerOptions { PropertyNamingPolicy = JsonNamingPolicy.CamelCase });
var modifyJson = nodes.ToString();
但在 .NET 5 中这是不可能的。演示 fiddle #3 here.