自定义Asp.net Core中向前台传递时间的格式

记录一下如何在Asp.net Core项目中自定义返回给前台的时间格式,如果不做设置返回前台的时间将会带一个 T,使用一下格式可以自定义传回前台为 YYYY-MM-dd或 YYYY-mm-dd HH:mm:ss

环境

Visual studio 2022, .Net 6.0

代码

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

namespace ApiProj.utilities
{
    public class DateConverter : JsonConverter<DateTime>
    {
        public override DateTime Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
        {
            if (reader.TokenType == JsonTokenType.String)
            {
                if (DateTime.TryParse(reader.GetString(), out DateTime date))
                    return date;
            }
            return reader.GetDateTime();
        }

        public override void Write(Utf8JsonWriter writer, DateTime value, JsonSerializerOptions options)
        {
            writer.WriteStringValue(value.ToString("yyyy-MM-dd"));
        }
    }
    public class DateTimeConverter : JsonConverter<DateTime>
    {
        public override DateTime Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
        {
            if (reader.TokenType == JsonTokenType.String)
            {
                if (DateTime.TryParse(reader.GetString(), out DateTime date))
                    return date;
            }
            return reader.GetDateTime();
        }

        public override void Write(Utf8JsonWriter writer, DateTime value, JsonSerializerOptions options)
        {
            writer.WriteStringValue(value.ToString("yyyy-MM-dd HH:mm:ss"));
        }
    }

    public class MillisecondTimeConverter : JsonConverter<DateTime>
    {
        public override DateTime Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
        {
            if (reader.TokenType == JsonTokenType.String)
            {
                if (DateTime.TryParse(reader.GetString(), out DateTime date))
                    return date;
            }
            return reader.GetDateTime();
        }

        public override void Write(Utf8JsonWriter writer, DateTime value, JsonSerializerOptions options)
        {
            writer.WriteStringValue(value.ToString("yyyy-MM-dd HH:mm:ss.fff"));
        }
    }

    public class DateTimeNullableConverter : JsonConverter<DateTime?>
    {
        public override DateTime? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
        {
            if (reader.TokenType == JsonTokenType.String)
            {
                if (DateTime.TryParse(reader.GetString(), out DateTime date)) return date;
                return default(DateTime?);

            }
            return reader.GetDateTime();
        }

        public override void Write(Utf8JsonWriter writer, DateTime? value, JsonSerializerOptions options)
        {
            writer.WriteStringValue(value?.ToString("yyyy-MM-dd HH:mm:ss"));
        }
    }

    public class DateNullableConverter : JsonConverter<DateTime?>
    {
        public override DateTime? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
        {
            if (reader.TokenType == JsonTokenType.String)
            {
                if (DateTime.TryParse(reader.GetString(), out DateTime date)) return date;
                return default(DateTime?);

            }
            return reader.GetDateTime();
        }

        public override void Write(Utf8JsonWriter writer, DateTime? value, JsonSerializerOptions options)
        {
            writer.WriteStringValue(value?.ToString("yyyy-MM-dd"));
        }
    }

}

其中包含两种转换的方式,一种为DateTime另一种为DateTime?,使用时需要注意DateTime是否会为空.

注册服务

在Program.cs中添加

builder.Services.AddControllersWithViews().AddJsonOptions(options =>
{
    options.JsonSerializerOptions.Converters.Add(new DateTimeConverter());
    options.JsonSerializerOptions.Converters.Add(new DateTimeNullableConverter());
});

使用

在类中直接使用注解的形式

using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Text.Json.Serialization;
using ApiProj.utilities;
using Microsoft.EntityFrameworkCore;

namespace ApiProj.Model
{
    [Table("User_info")]
    public class UserInfo
    {
        [Key]
        [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
        public int Id { get; set; }
        public string account { get; set; }
        public string name { get; set; }
        public string password { get; set; }
        public int phone { get; set; }
        public string sex { get; set; }
        [Column("create_time")]
        [DataType(DataType.Date)]
        [JsonConverter(typeof(DateNullableConverter))]
        public DateTime? createTime { get; set; }


    }
}