问题描述

有没有办法使用 Json.NET 序列化程序但不使用 JsonIgnore 属性?

Is there a way to ignore get-only properties using the Json.NET serializer but without using JsonIgnore attributes?

例如，我有一个具有这些获取属性的类:

For example, I have a class with these get properties:

    public Keys Hotkey { get; set; }

    public Keys KeyCode
    {
        get
        {
            return Hotkey & Keys.KeyCode;
        }
    }

    public Keys ModifiersKeys
    {
        get
        {
            return Hotkey & Keys.Modifiers;
        }
    }

    public bool Control
    {
        get
        {
            return (Hotkey & Keys.Control) == Keys.Control;
        }
    }

    public bool Shift
    {
        get
        {
            return (Hotkey & Keys.Shift) == Keys.Shift;
        }
    }

    public bool Alt
    {
        get
        {
            return (Hotkey & Keys.Alt) == Keys.Alt;
        }
    }

    public Modifiers ModifiersEnum
    {
        get
        {
            Modifiers modifiers = Modifiers.None;

            if (Alt) modifiers |= Modifiers.Alt;
            if (Control) modifiers |= Modifiers.Control;
            if (Shift) modifiers |= Modifiers.Shift;

            return modifiers;
        }
    }

    public bool IsOnlyModifiers
    {
        get
        {
            return KeyCode == Keys.ControlKey || KeyCode == Keys.ShiftKey || KeyCode == Keys.Menu;
        }
    }

    public bool IsValidKey
    {
        get
        {
            return KeyCode != Keys.None && !IsOnlyModifiers;
        }
    }

我是否需要将 [JsonIgnore] 添加到所有这些(我还有许多其他类)，或者有更好的方法来忽略所有仅获取属性?

Do I need to add [JsonIgnore] to all of them (I also have many other classes), or there is better way to ignore all get-only properties?

推荐答案

您可以通过实现自定义 IContractResolver 并在序列化期间使用它来做到这一点.如果您将 DefaultContractResolver 子类化，这将变得非常容易:

You can do this by implementing a custom IContractResolver and using that during serialization. If you subclass the DefaultContractResolver, this becomes very easy to do:

class WritablePropertiesOnlyResolver : DefaultContractResolver
{
    protected override IList<JsonProperty> CreateProperties(Type type, MemberSerialization memberSerialization)
    {
        IList<JsonProperty> props = base.CreateProperties(type, memberSerialization);
        return props.Where(p => p.Writable).ToList();
    }
}

这是一个演示如何使用它的测试程序:

Here is a test program demonstrating how to use it:

using System;
using System.Collections.Generic;
using System.Linq;
using Newtonsoft.Json;
using Newtonsoft.Json.Serialization;

class Program
{
    static void Main(string[] args)
    {
        Widget w = new Widget { Id = 2, Name = "Joe Schmoe" };

        JsonSerializerSettings settings = new JsonSerializerSettings
        {
            ContractResolver = new WritablePropertiesOnlyResolver()
        };

        string json = JsonConvert.SerializeObject(w, settings);

        Console.WriteLine(json);
    }
}

class Widget
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string LowerCaseName
    {
        get { return (Name != null ? Name.ToLower() : null); }
    }
}

这是上面的输出.请注意，只读属性 LowerCaseName 未包含在输出中.

Here is the output of the above. Notice that the read-only property LowerCaseName is not included in the output.

{"Id":2,"Name":"Joe Schmoe"}

这篇关于有没有办法在不使用 JsonIgnore 属性的情况下忽略 Json.NET 中的 get-only 属性?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持编程学习网！