设置DateTime格式-如何将值保留为DateTime格式？

Question

I have a DateTime being created in the format dd/MM/yyyy HH:mm:ss . I am writing code that interacts with a third-party SOAP library that requires a DateTime variable, in the format yyyy-MM-dd HH:mm:ss .

How do I change the way the information is stored in the DateTime variable, for the purpose of the call to the third-party SOAP library, ie no system-wide changes to dates?

I have investigated CultureInfo, which is mildly confusing and possibly too permanent a solution; the only time I need the DateTime changing is for an instance of this single call.

As an explanation, the library has a function GetOrders(DateTime startDate, DateTime endDate, TradingRoleCodeType roleType, OrderStatusCodeType statusType) . When attempting to perform the function with DateTimes as created, it generates an error "Sorry, the end date was missing, invalid, or before the start date. must be in YYYY-MM-DD or YYYY-MM-DD HH:MI:SS format, and after the start date.". Given the format that is passed in as dd/MM/yyyy HH:mm:ss , I'd think this may be the problem.

Answer 1

I have a DateTime being created in the format dd/MM/yyyy HH:ii:ss

No, you do not. You have a DateTime. It has no format. It is a number - which is well documented, you know, in the documentation. The string form is never used in a stored DateTime, only when generating the string for presentation.

How do I change the way the information is stored in the DateTime variable, for the purpose of the call to the third-party SOAP library, ie no system-wide changes to dates?

You do not. I would suggest you talk to your SOAP library - and it is not SOAP btw., IIRC the format you give as example is not valid in SOAP. Yes, bad news. Someone wants Pseudo-Soap.

http://www.w3schools.com/schema/schema_dtypes_date.asp

describes all valid date, time and datetime formats and yours is NOT there.

You can change the default format on a thread level back and forth, so one solution is to set it before calls into the soap library. Another one is to have someone fix the SOAP layer to accept standard formats.

Answer 2

You can create a dummy date :

public class SomeClass
{
    [XmlIgnore]
    public DateTime SomeDate { get; set; }

    [XmlElement("SomeDate")]
    public string SomeDateString
    {
        get { return this.SomeDate.ToString("yyyy-MM-dd HH:mm:ss"); }
        set { this.SomeDate = DateTime.Parse(value); }
    }
}

Source : Force XmlSerializer to serialize DateTime as 'YYYY-MM-DD hh:mm:ss' --kbrimington

Answer 3

As it turns out, the problem - as some have pointed out - is not to do with the variable being a DateTime, nor its "format" which is not a "format", but is certainly the representation of the information in a method to be understood.

The basic issue with the information was a DateTime comparison between standard time and UTC time. The third-party library examined the DateTime as a UTC DateTime, which when at the right time of year to be caught with a difference in times can cause a problem comparing a DateTime; despite being presented as after the reference time to the user, the time is actually before the reference time when being calculated, meaning the comparison fails.

The main takeaway for this question is to interrogate the information being passed to functions, if you don't have access to third-party library code nor access to documentation with sufficient detail, and errors are occurring when interacting with said third-party code.

Particularly, test various use cases to determine what variable values cause a failure and which cause successful execution of code; identify a pattern, and then test specific use cases that confirm the pattern. From there, determine the actual error that is occurring and code to fix the issue.

In the case of DateTimes, where the code understands DateTimeKinds such as C#, remember to test the different DateTimeKinds to establish whether they can be a part of the problem; its not happened to me often, but it has happened (as evidenced by this question).

Finally, error codes don't help much, and can lead to poor questions and poor advice; trial and error appears to be the best in cases similar to this.

Answer 4

You don't need to change how it's stored, as already mentioned above. You need to format is as a string according to ISO8601, which is what your SOAP service expects datetime parameter to be.

Check How to parse and generate DateTime objects in ISO 8601 format and

Given a DateTime object, how do I get an ISO 8601 date in string format?