Xsd.exe + json.如何处理xxx指定的生成成员

Question

当使用XSD.EXE从XML Schema生成类时，它生成给定对象的任何原语的xxxSpecified成员:

<xs:complexType name ="Foo">
    <xs:all>
      <xs:element name ="Count" type = "xs:integer"/>
    </xs:all>
</xs:complexType>

…生成:

public class Foo
{
    public int Count { get; set; }
    public bool CountSpecified { get; set; }
}

显示JSON的最新版本。. NET可以在反序列化时自动设置这些属性。

string request = "{ Count : 10 }";
var object = JsonConvert.Deserialize<Foo>(request)
Assert.IsTrue(object.Count = 10); // Yup
Assert.IsTrue(object.CountSpecified == true);  //Also yup - JSON.NET works!

然而，当采用另一种方式时，xxxSpecified属性包含在JSON输出中，这是不正确的，因为它不是模式的一部分。

string request = JsonConvert.Serialize(object); 
//{  
//   Count: 10, 
//   CountSpecified : true    <-- This is incorrect - should not be output 
//}

是否缺少控制是否输出xxxSpecified属性的设置?我怎样才能抑制它呢?

(注意:这是这里回答的问题的排列:

JSON。. NET、XmlSerializer和"指定的"地产

…但它涉及到创建扩展类，这对我来说是不可能的，因为模式中有数百个类，我不能改变继承层次结构。所以这个答案行不通。

Answer 1

您可以创建自己的契约解析器来过滤掉xxxSpecified属性:

public class SkipSpecifiedContractResolver : DefaultContractResolver
{
    // As of 7.0.1, Json.NET suggests using a static instance for "stateless" contract resolvers, for performance reasons.
    // http://www.newtonsoft.com/json/help/html/ContractResolver.htm
    // http://www.newtonsoft.com/json/help/html/M_Newtonsoft_Json_Serialization_DefaultContractResolver__ctor_1.htm
    // "Use the parameterless constructor and cache instances of the contract resolver within your application for optimal performance."
    static SkipSpecifiedContractResolver instance;
    static SkipSpecifiedContractResolver() { instance = new SkipSpecifiedContractResolver(); }
    public static SkipSpecifiedContractResolver Instance { get { return instance; } }
    protected override IList<JsonProperty> CreateProperties(Type type, MemberSerialization memberSerialization)
    {
        var properties = base.CreateProperties(type, memberSerialization);
        ILookup<string, JsonProperty> lookup = null;
        foreach (var property in properties)
        {
            if (property.GetIsSpecified != null && property.SetIsSpecified != null)
            {
                var name = property.UnderlyingName + "Specified";
                lookup = lookup ?? properties.ToLookup(p => p.UnderlyingName);
                var specified = lookup[name]
                    // Possibly also check for [XmlIgnore] being applied.  While not shown in the question, xsd.exe will always
                    // apply [XmlIgnore] to xxxSpecified tracking properties.
                    //.Where(p => p.AttributeProvider.GetAttributes(typeof(System.Xml.Serialization.XmlIgnoreAttribute),true).Any())
                    .SingleOrDefault();
                if (specified != null)
                    specified.Ignored = true;
            }
        }
        return properties;
    }
}

然后像这样使用:

var settings = new JsonSerializerSettings { ContractResolver = SkipSpecifiedContractResolver.Instance };
var object = JsonConvert.DeserializeObject<Foo>(request, settings);

如果您希望始终这样做，您可以在全局JsonConvert.DefaultSettings中设置契约解析器:

JsonConvert.DefaultSettings = (() =>
{
    return new JsonSerializerSettings { ContractResolver = SkipSpecifiedContractResolver.Instance };
});