JsonSerializerSettings 更改属性名称的大小写，但不更改属性的名称

Question

我将以下设置用于我的类属性的驼峰式外壳。

JsonSerializerSettings settings = new JsonSerializerSettings()
        {
            ContractResolver = new Newtonsoft.Json.Serialization.CamelCasePropertyNamesContractResolver()
        };

对象中的某些属性属于其他类类型。我不想更改这些属性的大小写。

例如：

Public Class CaseToChange
{
    public string StringProperty{get;set;} //Change to camelCase
    public SomeOtherType OtherTypeProperty{get;set;} //Change name of this to camelCase but not property name of "SomeOtherType"

}

如何使用 JsonSerializerSettings 实现这一点？

Answer 1

如果您可以修改您的类型以添加​​Json.NET serialization attributes，最简单的做法是将[JsonObject(NamingStrategyType = typeof(CamelCaseNamingStrategy))] 添加到您的CaseToChange 类型：

[JsonObject(NamingStrategyType = typeof(CamelCaseNamingStrategy))]
public class CaseToChange
{
    public string StringProperty { get; set; } //Change to camelCase
    public SomeOtherType OtherTypeProperty { get; set; } //Change name of this to camelCase but not property name of "SomeOtherType"
}

（或者，如果您使用的是早于 9.0.1 的 Json.NET 版本，请将 [JsonProperty("camelCaseName")] 添加到每个属性中，如 this answer。）

如果您无法修改类型并且必须仅通过序列化程序设置对CaseToChange 的属性进行驼峰式大小写，您可以创建一个custom contract resolver，它返回CaseToChange 的驼峰式名称和其他类型的未修改名称。以下是诀窍：

public class OverrideContractResolver : ContractResolverDecorator
{
    readonly Dictionary<Type, IContractResolver> overrides;

    public OverrideContractResolver(IEnumerable<KeyValuePair<Type, IContractResolver>> overrides, IContractResolver baseResolver)
        : base(baseResolver)
    {
        if (overrides == null)
            throw new ArgumentNullException();
        this.overrides = overrides.ToDictionary(p => p.Key, p => p.Value);
    }

    public override JsonContract ResolveContract(Type type)
    {
        IContractResolver resolver;
        if (overrides.TryGetValue(type, out resolver))
            return resolver.ResolveContract(type);
        return base.ResolveContract(type);
    }
}

public class ContractResolverDecorator : IContractResolver
{
    readonly IContractResolver baseResolver;

    public ContractResolverDecorator(IContractResolver baseResolver)
    {
        if (baseResolver == null)
            throw new ArgumentNullException();
        this.baseResolver = baseResolver;
    }

    #region IContractResolver Members

    public virtual JsonContract ResolveContract(Type type)
    {
        return baseResolver.ResolveContract(type);
    }

    #endregion
}

然后按如下设置进行序列化：

var settings = new JsonSerializerSettings
{
    ContractResolver =
        new OverrideContractResolver(
            new Dictionary<Type, IContractResolver> { { typeof(CaseToChange), new Newtonsoft.Json.Serialization.CamelCasePropertyNamesContractResolver() } },
            new Newtonsoft.Json.Serialization.DefaultContractResolver()),
};

生成的 JSON 将如下所示：

{
  "stringProperty": "string property",
  "otherTypeProperty": {
    "FooProperty": "foo",
    "BarProperty": 101
  }
}

示例fiddle。

为了获得最佳性能，您可能需要cache instances of the contract resolver。

Answer 2

只需添加如下所示的 JsonProperty 属性，如果您不希望整个对象树使用驼峰式命名，请不要使用 CamelCasePropertyNamesContractResolver。

public class CaseToChange
{
    [JsonProperty("stringProperty")]
    public string StringProperty { get; set; } //Change to camelCase

    [JsonProperty("otherTypeProperty")]
    public SomeOtherType OtherTypeProperty { get; set; } //Change name of this to camelCase but not property name of "SomeOtherType"
}