IM_NEW/MessageService.Domain/KeyObjects/MessageContent.cs

using System.ComponentModel.DataAnnotations.Schema;
using System.Text.Json;
using System.Text.Json.Serialization;

namespace MessageService.Domain.KeyObjects
{
    public class MessageContent
    {
        // 兜底文本
        [JsonPropertyName("fallback")]
        public string Fallback { get; init; }

        // 核心 Payload，反序列化时根据外层 MessageType 转换为具体子类
        public string RawBody { get; init; }
        public string RawExt { get; set; } = string.Empty;
        [JsonPropertyName("body")]
        // 业务代码使用的对象
        [NotMapped]
        public object Body => string.IsNullOrEmpty(RawBody) ? null : JsonSerializer.Deserialize<object>(RawBody);

        [NotMapped]
        public Dictionary<string, string> Ext => string.IsNullOrEmpty(RawExt)
            ? new()
            : JsonSerializer.Deserialize<Dictionary<string, string>>(RawExt);

        // 引用信息
        [JsonPropertyName("quote")]
        public QuoteInfo Quote { get; set; } = new();

        private MessageContent() { }
        public MessageContent(string fallback, object body)
        {
            Fallback = fallback;
            RawBody = body == null ? null : JsonSerializer.Serialize(body);
        }
    }
}