JSON.NET反序列化属性名称的接口
问题描述:
我有一个JSON字符串,例如JSON.NET反序列化属性名称的接口
{
"first_name": "Paul"
"company": {
"company_name": "Microsoft"
}
}
和我的课是在下面的结构
[DataContract]
class User {
[DataMember(Name = "first_name")]
public string FirstName { get; set; }
[DataMember(Name = "company")]
public ICompany Company { get; set; }
}
interface ICompany {
string CompanyName { get; set; }
}
[DataContract]
class Company : ICompany {
[DataMember(Name = "company_name")]
public string CompanyName { get; set; }
}
我使用自定义的自动解析刚刚发现使用autofac一个接口的实现(从json.net网站拉)
public class AutofacContractResolver : DefaultContractResolver
{
private readonly IContainer _container;
public AutofacContractResolver(IContainer container)
{
_container = container;
}
protected override JsonObjectContract CreateObjectContract(Type objectType)
{
JsonObjectContract contract = base.CreateObjectContract(objectType);
// use Autofac to create types that have been registered with it
if (_container.IsRegistered(objectType))
{
contract.DefaultCreator =() => _container.Resolve(objectType);
}
return contract;
}
}
然后我使用反序列化json字符串使用
User user = JsonConvert.DeserializeObject<User>(json, new JsonSerializerSettings
{
ContractResolver = _resolver,
});
现在,当我反序列化json时,first_name被序列化为FirstName属性,但是company_name没有,它只是返回null。当我使用TraceWriter时,它指出它无法在ICompany接口上找到名为company_name的成员(显然它不能在公司对象类中设置)
为什么JSON.NET不使用DataMember名称公司反对反序列化?因为它知道来自自定义解析器的Compmany对象,并且它创建了该对象,但没有内部值。
我怎样才能得到它使用接口的实现而不是接口本身?
仅供参考,这不是整个对象,我不能只是将我的属性更改为类而不是接口。这仅仅是所有界面对象发生变化的简单例子。
答
我刚刚遇到同样的问题,在寻找答案时,我在这里发现了您的旧问题。其实你问的方式让我走上了正轨,我解决了这个问题。以下适用于我:
我不使用Autofac,所以这是伪代码。但它应该足以理解它:
public class AutofacContractResolver : DefaultContractResolver
{
private readonly IContainer _container;
public AutofacContractResolver(IContainer container)
{
_container = container;
}
protected override JsonObjectContract CreateObjectContract(Type objectType)
{
JsonObjectContract contract;
// use Autofac to create types that have been registered with it
if (_container.IsRegistered(objectType))
{
//get the class that is mapped to the interface from autofac
Type mappedType = _container.GetMappedTypeForRegisteredType(objectType);
//so for example when objectType now contains 'ICompany'
//then mappedType now should contain 'Company'
//now use the mappedType to create the contract
contract = base.CreateObjectContract(mappedType);
//but still use the objectType for resolving
contract.DefaultCreator =() => _container.Resolve(objectType);
}
else
contract = base.CreateObjectContract(objectType);
return contract;
}
}
合同应该使用在依赖容器而不是接口中注册的具体实现来创建。 从DefaultCreator的容器中解析类型显然应该仍然使用该接口。