使用 JsonConverter 将日期 UTC 转换为特定时区答案

【问题标题】：Convert date UTC to a specific timezone using a JsonConverter使用 JsonConverter 将日期 UTC 转换为特定时区
【发布时间】：2020-08-15 11:49:41
【问题描述】：

我很抱歉我的格式化。

我收到来自数据库的 JSON 响应，我需要将日期转换为他/她所在的每个用户时区。我收到的用户时区为“时区”：5.5 或“时区”：-6 .

仅供参考，我的应用程序正在 Azure 中运行。我还应该检查时区的夏令时。应用程序是用 c# 开发的。我试过this 和this 看起来 Nodatime 适合根据时区转换日期。我对此完全陌生，并试图弄清楚如何根据时区更改 JSON 中的日期值。

我尝试了下面的代码来查看日期是否发生变化，但没有任何反应。我不确定我可以把时区放在哪里。任何帮助表示赞赏。

 ` var date = "2020-08-12T18:30:13.000";
    var json = $"{{\"Date\": \"{date}\"}}";

    var pattern = ZonedDateTimePattern.CreateWithInvariantCulture(
        "yyyy-MM-dd HH:mm:ss z",
        DateTimeZoneProviders.Tzdb
    );

    var settings = new JsonSerializerSettings
    {
        DateParseHandling = DateParseHandling.None,
        Converters = { new NodaPatternConverter<ZonedDateTime>(pattern) }
    };
    var dateObj = JsonConvert.DeserializeObject<DateObj>(json, settings);
    Console.WriteLine(dateObj.Date);`

下面是我收到的 JSON

{
"entity": [
    {
        "JobId": 691230,
        "Operation Type": "Backup",
        "Client": "cnwxwdevwms01",
        "Agent": "Oracle Database",
        "Instance": "T0340X",
        "BackupSet": "default",
        "Subclient": "ArchiveLog",
        " Backup Type": "Full",
        "Start Time": "2020-08-12T18:30:16.000",
        "End Time": "2020-08-12T18:32:04.000",
        "Duration in Mins": 2,
        "Size of Application": 315621376,
        "Job Status": "Completed",
        "dt": "2020-08-12T00:00:00.000",
        "age": 0,
        "original_0": {
            "numberOfDays": "10",
            "serverName": "cnwxwdevwms01"
        }
    },
    {
        "JobId": 691230,
        "Operation Type": "Backup",
        "Client": "cnwxwdevwms01",
        "Agent": "Oracle Database",
        "Instance": "T0340X",
        "BackupSet": "default",
        "Subclient": "ArchiveLog",
        " Backup Type": "Full",
        "Start Time": "2020-08-12T18:30:16.000",
        "End Time": "2020-08-12T18:32:04.000",
        "Duration in Mins": 2,
        "Size of Application": 315621376,
        "Job Status": "Completed",
        "dt": "2020-08-12T00:00:00.000",
        "age": 0,
        "original_0": {
            "numberOfDays": "10",
            "serverName": "cnwxwdevwms01"
        }
    },
    {
        "JobId": 694338,
        "Operation Type": "Backup",
        "Client": "cnwxwdevwms01",
        "Agent": "Oracle Database",
        "Instance": "T0340X",
        "BackupSet": "default",
        "Subclient": "ArchiveLog",
        " Backup Type": "Full",
        "Start Time": "2020-08-13T12:30:15.000",
        "End Time": "2020-08-13T12:32:07.000",
        "Duration in Mins": 2,
        "Size of Application": 282066944,
        "Job Status": "Completed",
        "dt": "2020-08-13T00:00:00.000",
        "age": 0,
        "original_0": {
            "numberOfDays": "10",
            "serverName": "cnwxwdevwms01"
        }
    },
    {
        "JobId": 693664,
        "Operation Type": "Backup",
        "Client": "cnwxwdevwms01",
        "Agent": "Oracle Database",
        "Instance": "T0340X",
        "BackupSet": "default",
        "Subclient": "ArchiveLog",
        " Backup Type": "Full",
        "Start Time": "2020-08-13T06:30:24.000",
        "End Time": "2020-08-13T06:32:13.000",
        "Duration in Mins": 2,
        "Size of Application": 255852544,
        "Job Status": "Completed",
        "dt": "2020-08-13T00:00:00.000",
        "age": 0,
        "original_0": {
            "numberOfDays": "10",
            "serverName": "cnwxwdevwms01"
        }
    },
    {
        "JobId": 692966,
        "Operation Type": "Backup",
        "Client": "cnwxwdevwms01",
        "Agent": "Windows File System",
        "Instance": "N/A",
        "BackupSet": "defaultBackupSet",
        "Subclient": "default",
        " Backup Type": "Incremental",
        "Start Time": "2020-08-13T02:00:19.000",
        "End Time": "2020-08-13T04:00:14.000",
        "Duration in Mins": 120,
        "Size of Application": 514155115394,
        "Job Status": "Completed",
        "dt": "2020-08-13T00:00:00.000",
        "age": 0,
        "original_0": {
            "numberOfDays": "10",
            "serverName": "cnwxwdevwms01"
        }
    },
    {
        "JobId": 692656,
        "Operation Type": "Backup",
        "Client": "cnwxwdevwms01",
        "Agent": "Oracle Database",
        "Instance": "T0340X",
        "BackupSet": "default",
        "Subclient": "ArchiveLog",
        " Backup Type": "Full",
        "Start Time": "2020-08-13T00:30:17.000",
        "End Time": "2020-08-13T00:32:13.000",
        "Duration in Mins": 2,
        "Size of Application": 124780544,
        "Job Status": "Completed",
        "dt": "2020-08-13T00:00:00.000",
        "age": 0,
        "original_0": {
            "numberOfDays": "10",
            "serverName": "cnwxwdevwms01"
        }
    },
    {
        "JobId": 691827,
        "Operation Type": "Backup",
        "Client": "cnwxwdevwms01",
        "Agent": "Oracle Database",
        "Instance": "T0340X",
        "BackupSet": "default",
        "Subclient": "default",
        " Backup Type": "Incremental",
        "Start Time": "2020-08-12T21:00:24.000",
        "End Time": "2020-08-12T22:51:53.000",
        "Duration in Mins": 111,
        "Size of Application": 683671552,
        "Job Status": "Completed",
        "dt": "2020-08-13T00:00:00.000",
        "age": 1,
        "original_0": {
            "numberOfDays": "10",
            "serverName": "cnwxwdevwms01"
        }
    },
    {
        "JobId": 691230,
        "Operation Type": "Backup",
        "Client": "cnwxwdevwms01",
        "Agent": "Oracle Database",
        "Instance": "T0340X",
        "BackupSet": "default",
        "Subclient": "ArchiveLog",
        " Backup Type": "Full",
        "Start Time": "2020-08-12T18:30:16.000",
        "End Time": "2020-08-12T18:32:04.000",
        "Duration in Mins": 2,
        "Size of Application": 315621376,
        "Job Status": "Completed",
        "dt": "2020-08-13T00:00:00.000",
        "age": 1,
        "original_0": {
            "numberOfDays": "10",
            "serverName": "cnwxwdevwms01"
        }
    }
]
}

【问题讨论】：

日期是否以 UTC 格式存储在您的数据库中？通常，如果它们的格式如下：'2020-08-12T18:30:13.000Z'。如果他们不是 UTC，你怎么知道他们将使用哪个时区？
嗨，Jukien，是的，日期是 UTC。
以后，请不要删除一个问题，然后稍微改变一下。相反，编辑现有问题。

标签： c# asp.net .net .net-core nodatime

【解决方案1】：

让我知道这是否适合你。

我没有使用 Nodatime，因为我认为它对于时区转换没有必要。我看到的问题是您的日期时间不包含任何时区信息。 .Net 将此作为本地处理。正如 Microsoft 文档所述： The time zone component of DateTimeKind.Utc date and time values uses "Z" (which stands for zero offset) to represent UTC.

编辑（根据@Sanjeev Gautam 的评论）：由于您的函数在 Azure 上运行，您需要找到一种方法来提取用户的本地时区。在下面的示例中，我使用了 UTC-9。

指定您的日期时间设置为 UTC 允许您这样做：

// Object Class
class DateObj
{
    public DateTime Date { get; set; }
}


// JsonConverter
class DateTimeConverterTimeZone : JsonConverter<DateTime>
{
    public TimeZoneInfo TimeZone { get; set; }

    public DateTimeConverterTimeZone(TimeZoneInfo timezone)
    {
        TimeZone = timezone;
    }

    public override void WriteJson(JsonWriter writer, DateTime value, JsonSerializer serializer)
    {
        writer.WriteValue(value.ToUniversalTime());
    }

    public override DateTime ReadJson(JsonReader reader, Type objectType, DateTime existingValue, bool hasExistingValue, JsonSerializer serializer)
    {
        DateTime  dt = (DateTime) reader.Value; 

        var newDateTime= TimeZoneInfo.ConvertTime(dt, TimeZone);
        return newDateTime;
    }
}

//Deserialization
var date = "2020-08-12T18:30:13.000Z";
var json = $"{{\"Date\": \"{date}\"}}";
var convertedDateTime = JsonConvert.DeserializeObject<DateObj>(json, new DateTimeConverterTimeZone(TimeZoneInfo.FindSystemTimeZoneById("UTC-09")));

【讨论】：

嗨朱利安，感谢您的回复。我不能选择 DateTimeZoneHandling.Local，因为我的应用程序在 Azure 中运行，它总是需要 Azure 时区。我们需要给用户时区。
@SanjeevGautam - 感谢您的评论。我省略了“Azure”部分，抱歉。我更新了响应以使用自定义 JsonConverter。
谢谢，它与日期共享。当我尝试使用我的实际 JSON 日期时没有转换。 var convertDateTimeFinal = JsonConvert.DeserializeObject(response.Content, new DateTimeConverterTimeZone(TimeZoneInfo.FindSystemTimeZoneById("UTC-09")));请提供任何帮助。
您分享的日期最后没有指定它是 UTC 日期的 Z。您是否尝试在 Json 中每个日期的末尾添加 Z ？
伟大的朱利安，你救了我:)。它就像一个魅力。