C# - 在 JSON 序列化和反序列化之间设置不同的 PropertyName

Question

我正在查询 API，响应是自定义的 JSON。在网上查看后，我设法通过这种方式将其反序列化为自定义对象：

Post.cs

[JsonConverter(typeof(JsonPathConverter))]
public class Post
{
    [JsonProperty(PropertyName = "id")]
    public string Id { get; set; }

    [JsonProperty(PropertyName = "taken_at_timestamp")]
    public long Timestamp { get; set; }

    [JsonProperty(PropertyName = "edge_media_preview_like.count")]
    public int LikeCount { get; set; }

    [JsonProperty(PropertyName = "edge_media_to_comment.count")]
    public int CommentCount { get; set; }

    [JsonProperty(PropertyName = "edge_media_to_caption.edges[0].node.text")]
    public string Caption { get; set; }

    [JsonProperty(PropertyName = "display_url")]
    public string Image { get; set; }

    [JsonProperty(PropertyName = "dimensions.width")]
    public int Width { get; set; }

    [JsonProperty(PropertyName = "dimensions.height")]
    public int Height { get; set; }

    [JsonProperty(PropertyName = "shortcode")]
    public string Shortcode { get; set; }
}

JsonPathConverter.cs

public class JsonPathConverter : JsonConverter
{
    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        JObject jo = JObject.Load(reader);
        object targetObj = Activator.CreateInstance(objectType);

        foreach (PropertyInfo prop in objectType.GetProperties().Where(p => p.CanRead && p.CanWrite))
        {
            JsonPropertyAttribute att = prop.GetCustomAttributes(true)
                                            .OfType<JsonPropertyAttribute>()
                                            .FirstOrDefault();

            string jsonPath = (att != null ? att.PropertyName : prop.Name);
            JToken token = jo.SelectToken(jsonPath);

            if (token != null && token.Type != JTokenType.Null)
            {
                object value = token.ToObject(prop.PropertyType, serializer);
                prop.SetValue(targetObj, value, null);
            }
        }

        return targetObj;
    }

    public override bool CanConvert(Type objectType)
    {
        return false;
    }

    public override bool CanWrite
    {
        get { return false; }
    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        throw new NotImplementedException();
    }
}

问题是当我想将该对象作为 JSON 发送时：它 returns 字段具有 PropertyName 值，而不是属性名称：

[
  {
    "id": "2322829435103312153",
    "taken_at_timestamp": 1591122868,
    "edge_media_preview_like.count": 24,
    "edge_media_to_comment.count": 0,
    "edge_media_to_caption.edges[0].node.text": "...",
    "display_url": "...",
    "dimensions.width": 1080,
    "dimensions.height": 1080,
    "shortcode": "..."
  }
  ...
]

有没有办法使用 PropertyName 进行反序列化，而使用属性名称进行序列化？

更新

应要求，我是这样使用反序列化和序列化的：

反序列化

JArray response = "[{ ... }]";

List<Post> posts = new List<Post>();

foreach (JObject node in response)
{
    Post post = JsonConvert.DeserializeObject<Post>(node.ToString());
    posts.Add(post);
}

序列化

我只是 return List 里面的一个“Ok” IActionResult:

Ok(posts);

Answer 1

您可以使用 ContractResolver 如下所示。

var jsondata = JsonConvert.SerializeObject(data, new JsonSerializerSettings { ContractResolver = new ShouldUseMemberNameContractResolver() });


public class ShouldUseMemberNameContractResolver : DefaultContractResolver
{
    public new static readonly ShouldUseMemberNameContractResolver Instance = new ShouldUseMemberNameContractResolver();

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

        if (property.DeclaringType == typeof(Post))
        {
            property.PropertyName = member.Name;
        }

        return property;
    }
}

Answer 2

我按照Chetan Ranpariya的建议通过WriteJson方法解决了：

public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
    JArray result = new JArray();

    if (value.GetType().IsGenericType && value is IEnumerable)
    {
        IEnumerable list = value as IEnumerable;

        foreach(var obj in list)
        {
            result.Add(GetObjectJson(obj));
        }
    }

    result.WriteTo(writer);
}

private JObject GetObjectJson(object obj)
{
    JObject jObj = new JObject();
    PropertyInfo[] props = obj.GetType().GetProperties();

    foreach (PropertyInfo prop in props)
    {
        if (!prop.PropertyType.ToString().Contains("System"))
            jObj.Add(char.ToLowerInvariant(prop.Name[0]) + prop.Name.Substring(1), GetObjectJson(prop.GetValue(obj)));
        else
            jObj.Add(char.ToLowerInvariant(prop.Name[0]) + prop.Name.Substring(1), JToken.FromObject(prop.GetValue(obj)));
    }

    return jObj;
}

与 object value 参数一样，我收到对象（在本例中是一个列表），我对其进行转换并遍历它的对象。

由于每个对象都可以具有原始属性和非原始属性，因此我创建了一个单独的函数来递归使用它，以防发现嵌套对象。

C# - 在 JSON 序列化和反序列化之间设置不同的 PropertyName

C# - Set different PropertyName between JSON serialization and deserialization

c#

json

json-deserialization