C# 替换JSON序列化上的敏感数据值

我想将一些对象序列化为JSON。但是，有些对象的属性通过属性被视为“敏感数据”

[SensitiveDataAttribute]
public string SomeSensitiveProperty {get; set;}

目前，我正在重写序列化程序上的“CreateProperty”方法，以便根据属性是否具有此“SensitiveData”属性来更改是否应序列化属性：

public class SensitiveDataResolver : DefaultContractResolver
    {
        protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
        {
            var property = base.CreateProperty(member, memberSerialization);
            property.ShouldSerialize = instance =>
            {
                if (member is PropertyInfo)
                {
                    var prop = (PropertyInfo) member;
                    var isSensitiveData = Attribute.IsDefined(prop, typeof (SensitiveDataAttribute));
                    return !isSensitiveData;
                }
                return false;
            };
            return property;
        }
    }
}

序列化时，我将使用该解析器作为序列化程序的设置：

var settings = new JsonSerializerSettings() { ContractResolver = new SensitiveDataResolver() };
var requestString = JsonConvert.SerializeObject(someObject, settings);

我的问题是，我不想从序列化中排除属性。我希望将它们序列化，但对它们设置默认值'SensitiveData'

---

有没有一种方法可以通过使用属性来实现这一点？

如果成员具有该属性，您可以直接重写属性值，而不是使用

ShouldSerialize

方法。为此，您需要为Json.NET提供自定义的

IValueProvider

，以便在序列化时使用

protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
{
    var property = base.CreateProperty(member, memberSerialization);

    if (member is PropertyInfo)
    {
        var prop = (PropertyInfo)member;
        var isSensitiveData = Attribute.IsDefined(prop, typeof (SensitiveDataAttribute));

        if (isSensitiveData)
            property.ValueProvider = new StringValueProvider("SensitiveData");
    }

    return property;
}

StringValueProvider

是

IValueProvider

接口的自定义实现

public class StringValueProvider : IValueProvider
{
    private readonly string _value;

    public StringValueProvider(string value)
    {
        _value = value;
    }

    public void SetValue(object target, object value)
    {
        throw new NotSupportedException();
    }

    public object GetValue(object target)
    {
        return _value;
    }
}

---

您可以覆盖属性值本身，而不是设置property.ShouldSerialize

public class SensitiveDataResolver : DefaultContractResolver
{
    protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
    {
        if (this.IsSensitiveProperty(member))
        {
            ((PropertyInfo)member).SetValue(member, "SensitiveData", null);
        }

        var property = base.CreateProperty(member, memberSerialization);
        return property;
    }

    private bool IsSensitiveProperty(MemberInfo member)
    {
        if (member is PropertyInfo)
        {
            var prop = (PropertyInfo) member;
            var isSensitiveData = Attribute.IsDefined(prop, typeof (SensitiveDataAttribute));
            return isSensitiveData;
        }
        return false;
    }
}

---

您可以在契约解析器中使用反射来实现这一点

PropertyInfo[] props = typeof(instanceOfMyClass).GetProperties();
foreach (PropertyInfo prop in props)
{
     object[] attrs = prop.GetCustomAttributes(true);
     foreach (object attr in attrs)
     {
           var sensitive = attr as SensitiveDataAttribute;
           if (sensitive != null)
           {
               //add the default value to your property here
              prop.SetValue(instanceOfMyClass, "Default Value", null);
          }
     }
}

---

为敏感数据属性实现

IValueProvider

，并将其用于PropertyValueProvider

public class SensitiveDataProvider : IValueProvider
{
    readonly string sesitiveDatatag = "Sensitive Data";
    public object GetValue(object target)
    {
        return sesitiveDatatag;
    }

    public void SetValue(object target, object value)
    {
        target = sesitiveDatatag;
    }
}

现在您的

DefaultContractResolver

将是：

    public class SensitiveDataResolver : DefaultContractResolver
    {
        protected override JsonProperty CreateProperty(MemberInfo member, MemberSerialization memberSerialization)
        {
            var property = base.CreateProperty(member, memberSerialization);

            if (member is PropertyInfo)
            {
                var prop = (PropertyInfo)member;
                var isSensitiveData = Attribute.IsDefined(prop, typeof(SensitiveDataAttribute));

                if(isSensitiveData)
                {
                    property.ValueProvider = new SensitiveDataProvider();
                }
            }

            return property;
        }
    }

---

这回答了你的问题吗？