UTC时间与本地时间转换问题

using System.Text.Json;
using System.Text.Json.Serialization;

namespace NDTInspHubCore.WebAPI.Converters
{
    /// <summary>
    /// UTC时间到本地时间的转换器
    /// </summary>
    public class UtcToLocalDateTimeConverter : JsonConverter<DateTime>
    {
        /// <summary>
        /// 读取JSON并转换为UTC时间
        /// </summary>
        public override DateTime Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
        {
            return DateTime.Parse(reader.GetString()!).ToUniversalTime();
        }

        /// <summary>
        /// 将UTC时间转换为本地时间并写入JSON
        /// </summary>
        public override void Write(Utf8JsonWriter writer, DateTime value, JsonSerializerOptions options)
        {
            writer.WriteStringValue(value.ToLocalTime().ToString("yyyy-MM-dd HH:mm:ss"));
        }
    }

    /// <summary>
    /// UTC时间到本地时间的转换器(可空)
    /// </summary>
    public class UtcToLocalNullableDateTimeConverter : JsonConverter<DateTime?>
    {
        /// <summary>
        /// 读取可空JSON并转换为UTC时间
        /// </summary>
        public override DateTime? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
        {
            if (reader.TokenType == JsonTokenType.Null)
            {
                return null;
            }
            return DateTime.Parse(reader.GetString()!).ToUniversalTime();
        }

        /// <summary>
        /// 将可空UTC时间转换为本地时间并写入JSON
        /// </summary>
        public override void Write(Utf8JsonWriter writer, DateTime? value, JsonSerializerOptions options)
        {
            if (value.HasValue)
            {
                writer.WriteStringValue(value.Value.ToLocalTime().ToString("yyyy-MM-dd HH:mm:ss"));
            }
            else
            {
                writer.WriteNullValue();
            }
        }
    }
}

import dayjs from 'dayjs'
import utc from 'dayjs/plugin/utc'
import timezone from 'dayjs/plugin/timezone'

dayjs.extend(utc)
dayjs.extend(timezone)

export const formatUTCTime = (time) => {
  return dayjs.utc(time).local().format('YYYY-MM-DD HH:mm:ss')
}

export const formatLocalTime = (time) => {
  return dayjs(time).format('YYYY-MM-DD HH:mm:ss')
}

export const convertLocalToUTC = (time) => {
  return dayjs(time).utc().format('YYYY-MM-DD HH:mm:ss')
}

program.cs

                .AddJsonOptions(options =>
                {
                    options.JsonSerializerOptions.WriteIndented = false;
                    options.JsonSerializerOptions.Converters.Add(new UtcToLocalDateTimeConverter());
                    options.JsonSerializerOptions.Converters.Add(new UtcToLocalNullableDateTimeConverter());
                });

    /// <summary>
    /// 配置映射关系
    /// </summary>
    public class AutoMapperConfig : Profile
    {
        /// <summary>
        /// 配置映射关系
        /// </summary>
        public AutoMapperConfig()
        {
            // 全局时间转换：UTC到本地时间
            CreateMap<DateTime, DateTime>().ConvertUsing(d => d.ToLocalTime());
            CreateMap<DateTime?, DateTime?>().ConvertUsing(d => d.HasValue ? d.Value.ToLocalTime() : (DateTime?)null);
            
        }
    }

API 返回序列化 json 时处理，在.NET Core的JSON全局转换中，系统识别UTC时间的关键在于DateTime结构的Kind属性及数据传输的隐式约定

优化方案：显式时区处理

方案一：数据库层标注时区(推荐)