评估时间为12小时格式的字符串时如何从convert.datetime（）获取24小时结果

Question

I have an API that returns an event date and event time, both as string values. In addition, the time is in 12 hour format with a trailing lowercase am or pm. For example,

"eventTime": "6:09 pm",
"eventDate": "February 8, 2017", 

And I am trying to save the date and time into a single datetime field in my database.

I am currently using...

DateTime eventDateTime = Convert.ToDateTime($"{a_item.EventDate} {a_item.EventTime}"; 

and then saving the eventDateTime value into a SQL Server 2008 R2 record field that is defined as ...

[EventDateTime] [datetime] NOT NULL, 

But when I look at the result in SQL Server, it is stored as if it was 24 hour time but ignoring the am or pm in the text that is being converted.

for example,

"eventTime": "6:09 pm",
"eventDate": "February 8, 2017", 

Shows up as

2017-02-08 06:09:00.000

Instead of

2017-02-08 18:09:00.000

What do I need to do so that the date and time get saved to the database in 24 hour format so my records will sort properly?

Here is the whole method.

private SaveRecordResult SaveMailPieceExtractRecord(MailEvent a_item, string a_eventSource)
{
    SaveRecordResult result = new SaveRecordResult();
    result.Success = false;
    try
    {
        if (a_item != null && !string.IsNullOrEmpty(a_item.Pic))
        {
            DateTime eventDateTime = DateTime.Now;
            if (!string.IsNullOrEmpty(a_item.EventDate) && !string.IsNullOrEmpty(a_item.EventTime))
            {
                eventDateTime = Convert.ToDateTime($"{a_item.EventDate} {a_item.EventTime}");  
            }

            string scanFacilityName = string.Empty;
            if (!string.IsNullOrEmpty(a_item.EventCity) && !string.IsNullOrEmpty(a_item.EventState))
            {
                scanFacilityName = $"{a_item.EventCity}, {a_item.EventState}";
            }


            MailPieceExtracts mailPieceExtract = new MailPieceExtracts
            {
                Pic = a_item.Pic,
                ExtractFileNumber = a_item.ExtractFileNumber,
                UspsmailerName = a_item.UspsMailerName,
                UspsmailerId = a_item.UspsMailerId,
                DestinationZip = a_item.DestinationZip,
                ScanFacilityZip = a_item.EventZipCode,
                ScanFacilityName = scanFacilityName,
                EventCode = a_item.EventCode,
                EventName = a_item.Event,
                EventDateTime = eventDateTime,
                CountryCode = a_item.EventCountry,
                Recipient = (!String.IsNullOrEmpty(a_item.Name)) ? a_item.Name : a_item.FirmName,
                FileReceivedDate = DateTime.Now,
                CreatedBy = a_eventSource
            };
            m_cdiMainContext.MailPieceExtracts.Add(mailPieceExtract);
            m_cdiMainContext.SaveChanges();
            result.Success = true;
            result.Error = string.Empty;
        }
        return result;
    }
    catch (Exception ex)
    {
        m_logger.LogError(2, ex, "An exception occurred while tryin to save the MailPiece_Extract record for Mail Event : [{@MailEvent}]", a_item);
        string errorMessage = $"Could not save MailPiece_Extracts record for PIC {a_item.Pic} to the database.";
        result.Error = $"{errorMessage}. The error message is [{ex.Message}]";
        return result;
    }

}

In the MailPieceExtracts class, the EventDateTime is just an auto property..

public DateTime EventDateTime { get; set; }

Thanks in advance for any help you can provide.

Answer 1

Instead of using Convert.ToDateTime , use DateTime.TryParseExact :

if(DateTime.TryParseExact($"{a_item.EventDate} {a_item.EventTime}", "MMMM d, yyyy h:mm tt", CultureInfo.InvariantCulture, DateTimeStyles.None, out eventDateTime))
{
    // eventDateTime now holds correct datetime, assuming the data transfered was correct. 
}
else
{
    // Failed to parse string as datetime.
}

See live example on rextester.