基于.Net(C#)中的字段反序列化json
我正在编写一个应用程序,它将获得一个对象列表,如下所示:基于.Net(C#)中的字段反序列化json,c#,.net,json,field,deserialization,C#,.net,Json,Field,Deserialization,我正在编写一个应用程序,它将获得一个对象列表,如下所示: [ { "ObjectType": "apple", "ObjectSize": 35, "ObjectCost": 4, "ObjectTaste": "good", "ObjectColor": "golden" }, { "ObjectType": "books", "ObjectSize": 53, "
[
{
"ObjectType": "apple",
"ObjectSize": 35,
"ObjectCost": 4,
"ObjectTaste": "good",
"ObjectColor": "golden"
},
{
"ObjectType": "books",
"ObjectSize": 53,
"ObjectCost": 7,
"Pages": 100
},
{
"ObjectType": "melon",
"ObjectSize": 35,
"ObjectTaste": "good",
"ObjectCost": 5
},
{
"ObjectType": "apple",
"ObjectSize": 29,
"ObjectCost": 8,
"ObjectTaste": "almost good",
"ObjectColor": "red"
}
]
class MyItemConverter : JsonConverter
{
public override bool CanConvert(Type objectType)
{
return typeof(ItemToSell).IsAssignableFrom(objectType);
}
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
JObject obj = JObject.Load(reader);
string discriminator = (string)obj["ObjectType"];
ItemToSell item;
switch (discriminator)
{
case "apple":
item = new Apple();
break;
case "books":
item = new Books();
break;
case "melon":
item = new Melon();
break;
default:
throw new NotImplementedException();
}
serializer.Populate(obj.CreateReader(), item);
return item;
}
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
}
}
我想创建一个基类ItemToSell
(size,cost),并从中派生Apple、甜瓜和Book,然后根据“ObjectType
”字段将其反序列化为适合的任何类。我想让它建立一个ItemToSell
对象列表,每个对象都是苹果、甜瓜或书
我怎样才能在.Net中做到这一点
提前感谢:)
编辑:我知道如何在一个包含所有字段的大类中反序列化它,比如:Base(ObjectType、ObjectSize、ObjectCost、ObjectColor、Pages)
。但是我想让它通过ObjectType
来区分类,这样我就不会有任何有用的字段,比如每本书的Pages字段或者每本书的ObjectTaste
有了它,你可以做以下事情:
...
public class Movie
{
public string Name;
public DateTime ReleaseDate;
public string[] Genres;
}
......
string json = @"{
'Name': 'Bad Boys',
'ReleaseDate': '1995-4-7T00:00:00',
'Genres': [
'Action',
'Comedy'
]
}";
Movie m = JsonConvert.DeserializeObject<Movie>(json);
string name = m.Name;
// Bad Boys
。。。
公映
{
公共字符串名称;
公共日期时间发布日期;
公共字符串[]类型;
}
......
字符串json=@”{
“名字”:“坏男孩”,
“发布日期”:“1995-4-7T00:00:00”,
“流派”:[
“行动”,
“喜剧”
]
}";
Movie m=JsonConvert.DeserializeObject(json);
字符串名称=m.名称;
//坏小子
定义基类和派生类
使用[JSON.net](也可通过NuGet获得)对它们进行反序列化
即
然后使用
var catalog = JsonConvert.Deserialize<List<ItemToSell>>(json);
var catalog=JsonConvert.Deserialize(json);
反序列化程序将忽略意外属性。如果需要,请使用特定类型再次调用它以获取其他属性。不久前,我遇到了同样的问题 您可以使用Json.NET,但如果您无法控制Json文档(如:“它已被其他框架序列化”),则需要创建一个自定义JsonConverter,如下所示:
[
{
"ObjectType": "apple",
"ObjectSize": 35,
"ObjectCost": 4,
"ObjectTaste": "good",
"ObjectColor": "golden"
},
{
"ObjectType": "books",
"ObjectSize": 53,
"ObjectCost": 7,
"Pages": 100
},
{
"ObjectType": "melon",
"ObjectSize": 35,
"ObjectTaste": "good",
"ObjectCost": 5
},
{
"ObjectType": "apple",
"ObjectSize": 29,
"ObjectCost": 8,
"ObjectTaste": "almost good",
"ObjectColor": "red"
}
]
class MyItemConverter : JsonConverter
{
public override bool CanConvert(Type objectType)
{
return typeof(ItemToSell).IsAssignableFrom(objectType);
}
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
JObject obj = JObject.Load(reader);
string discriminator = (string)obj["ObjectType"];
ItemToSell item;
switch (discriminator)
{
case "apple":
item = new Apple();
break;
case "books":
item = new Books();
break;
case "melon":
item = new Melon();
break;
default:
throw new NotImplementedException();
}
serializer.Populate(obj.CreateReader(), item);
return item;
}
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
}
}
然后需要将其添加到JsonSerializerSettings的转换器中,如下所示:
JsonSerializerSettings settings = new JsonSerializerSettings
{
TypeNameHandling = TypeNameHandling.Objects,
};
settings.Converters.Add(new MyItemConverter());
var items = JsonConvert.DeserializeObject<List<ItemToSell>>(response, settings);
JsonSerializerSettings设置=新的JsonSerializerSettings
{
TypeNameHandling=TypeNameHandling.Objects,
};
添加(新的MyItemConverter());
var items=JsonConvert.DeserializeObject(响应、设置);
这不是答案,但在C#6.0中,您可以做到:
using Microsoft.VisualStudio.TestTools.UnitTesting;
using Newtonsoft.Json.Linq;
[TestMethod]
public void JsonWithDollarOperatorStringIndexers()
{
// Additional data types eliminated for elucidation
string jsonText = @"
{
'Byte': {
'Keyword': 'byte',
'DotNetClassName': 'Byte',
'Description': 'Unsigned integer',
'Width': '8',
'Range': '0 to 255'
},
'Boolean': {
'Keyword': 'bool',
'DotNetClassName': 'Boolean',
'Description': 'Logical Boolean type',
'Width': '8',
'Range': 'True or false.'
},
}";
JObject jObject = JObject.Parse(jsonText);
Assert.AreEqual("bool", jObject.$Boolean.$Keyword);
}
摘自您可以使用。这使您能够钩住反序列化过程
public abstract class Base
{
public string Type { get; set; }
}
class Foo : Base
{
public string FooProperty { get; set; }
}
class Bar : Base
{
public string BarProperty { get; set; }
}
class CustomSerializableConverter : CustomCreationConverter<Base>
{
public override Base Create(Type objectType)
{
throw new NotImplementedException();
}
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
var jObject = JObject.Load(reader);
var type = (string)jObject.Property("Type");
Base target;
switch (type)
{
case "Foo":
target = new Foo();
break;
case "Bar":
target = new Bar();
break;
default:
throw new InvalidOperationException();
}
serializer.Populate(jObject.CreateReader(), target);
return target;
}
}
class Program
{
static void Main(string[] args)
{
var json = "[{Type:\"Foo\",FooProperty:\"A\"},{Type:\"Bar\",BarProperty:\"B\"}]";
List<Base> bases = JsonConvert.DeserializeObject<List<Base>>(json, new CustomSerializableConverter());
}
}
公共抽象类基类
{
公共字符串类型{get;set;}
}
Foo类:Base
{
公共字符串属性{get;set;}
}
类别栏:基本
{
公共字符串属性{get;set;}
}
类CustomSerializableConverter:CustomCreationConverter
{
公共重写基创建(类型objectType)
{
抛出新的NotImplementedException();
}
公共重写对象ReadJson(JsonReader阅读器,类型objectType,对象existingValue,JsonSerializer序列化程序)
{
var jObject=jObject.Load(读卡器);
变量类型=(字符串)jObject.Property(“类型”);
基本目标;
开关(类型)
{
案例“Foo”:
target=newfoo();
打破
案例“酒吧”:
目标=新条();
打破
违约:
抛出新的InvalidOperationException();
}
填充(jObject.CreateReader(),目标);
回报目标;
}
}
班级计划
{
静态void Main(字符串[]参数)
{
var json=“[{Type:\'Foo\',FooProperty:\'A\'},{Type:\'Bar\',BarProperty:\'B\'}]”;
List base=JsonConvert.DeserializeObject(json,新的CustomSerializableConverter());
}
}
它不是有效的json,请确保它是完整的jsonOk我知道如何从json转换到c#类并反序列化对象,但我希望它基于ObjectType在列表中创建对象。不过还是要谢谢你的回答。