如何使用JsonConverter属性格式化日期列表 [英] How to format a list of dates using JsonConverter attribute

问题描述

我正在使用WebApi 2服务，该服务以JSON格式返回数据.我为DateTimes使用两种格式，日期:"2017-01-31"和日期时间:"2017-01-31T12:00:00.000Z".日期时间格式使用最多，因此我将其设置为global.asax中的默认格式:

I'm working on a WebApi 2 service that returns data in JSON format. I use two formats for DateTimes, date: "2017-01-31" and datetime: "2017-01-31T12:00:00.000Z". The datetime format is used the most so I've set this as the default in the global.asax:

config.Formatters.JsonFormatter.SerializerSettings.Converters.Add(new IsoDateTimeConverter() { DateTimeFormat = "yyyy'-'MM'-'dd'T'HH':'mm':'ss'.'fff'Z'" });

然后在需要格式化为日期的那些DateTime字段上使用一个自定义IsoDateTimeConverter的JsonConverter属性:

And I use a JsonConverter attribute using a custom IsoDateTimeConverter on those DateTime fields that need to be formatted as date:

public class Foo
{
    [JsonConverter(typeof(OnlyDateConverter))]
    public DateTime Bar { get; set; }
}

public class OnlyDateConverter : IsoDateTimeConverter
{
    public OnlyDateConverter()
    {
        DateTimeFormat = "yyyy-MM-dd";
    }
}

到目前为止，一切都很好，这就像一种魅力.

So far all is fine, this works like a charm.

但这是问题所在: 对于某些对象，我有一个DateTime对象列表，需要将其格式化为日期.但是JSON转换器似乎不支持在列表上使用JsonConverter属性.

But here's the problem: For some objects I have a list of DateTime objects that need to be formatted as date. But the JSON converter seems to not support using a JsonConverter attribute on a list.

public class Foo
{
    [JsonConverter(typeof(OnlyDateConverter))] // This works
    public DateTime Bar { get; set; }

    [JsonConverter(typeof(OnlyDateConverter))] // This does not work!
    public List<DateTime> Bars { get; set; }
}

这将导致以下错误:转换日期时出现意外值.预期的DateTime或DateTimeOffset，获得了System.Collections.Generic.List`1 [System.DateTime].

This results in the following error: Unexpected value when converting date. Expected DateTime or DateTimeOffset, got System.Collections.Generic.List`1[System.DateTime].

很清楚，您不能在日期列表上使用[JsonConverter(typeof(OnlyDateConverter))].但是，如何将日期时间列表格式化为日期呢?

Pretty clear, you can't use [JsonConverter(typeof(OnlyDateConverter))] on a list of dates. But then how do I format a list of DateTime as date?

我一直在寻找解决方案，但是除了创建一个仅包含一个带有属性的DateTime属性的类外，似乎找不到其他任何东西.但这对我来说似乎不正确.

I've been searching for a solution but can't seem to find anything other than creating a class that consists of just one DateTime property with the attribute. But that just doesn't seem right to me.

肯定有一种方法可以在DateTimes列表上使用JsonConverter属性吗?我在这里想念什么?

Surely there must be a way to use the JsonConverter attribute on a list of DateTimes? What am I missing here?

推荐答案

使用[JsonProperty(ItemConverterType = typeof(MyDateTimeConverter))]

use [JsonProperty(ItemConverterType = typeof(MyDateTimeConverter))]

这篇关于如何使用JsonConverter属性格式化日期列表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IT屋！