字符串未被识别为有效日期时间asp.net C＃

Question

when i got the above error i tried with datetime journeydate=datetime.parse.... but that also throws a error like a field initializer cant reference the non static field, method or property.

public class aaa
{
    public string created_date { get; set; }
    DateTime journeyDate = DateTime.ParseExact(created_date, "yyyy-MM-ddThh:mm:ss", CultureInfo.InvariantCulture); // error
}

This created_date will be retrived directly from db.. Is there any possible way to avoid the string was not recognized error?

Answer 1

Your date format is not even close to what you throw in there. You could have at least noticed yourself that the position of year doesn't match.

public class aaa
{
    public string created_date { get; set; }
    //This code "runs" so to say. You can't put that in a class. 
    //DateTime journeyDate = DateTime.ParseExact(created_date, "yyyy-MM-ddThh:mm:ss", CultureInfo.InvariantCulture);

    //Can't do this either, because when will it be called? "runable" code needs to be in a method.
    //for(int i = 0; i < created_date.length; i++){

    //We can however only decalre journeyDate
    private DateTime journeyDate;

    //And then use either a method or constructor to set it:

    public void InitializeJourneyDate()
    {
        journeyDate = DateTime.ParseExact(created_date, "yyyy-MM-ddThh:mm:ss", CultureInfo.InvariantCulture);
    }

    public aaa()
    {
        journeyDate = DateTime.ParseExact(created_date, "yyyy-MM-ddThh:mm:ss", CultureInfo.InvariantCulture);
    }

    //Maybe the best method is to use a property getter. This will return a diffrent datetime automatically when you change your string

    private DateTime JourneyDateProp
    {
        get
        {
            return DateTime.ParseExact(created_date, "yyyy-MM-ddThh:mm:ss", CultureInfo.InvariantCulture);
        }
    }

    public void Convert()
    {
        List<string> dateTimeStrings = new List<string>(){
            "2018-01-19T09:10:52",
            "2018-01-22T09:10:52",
            "2018-01-28T09:10:52"
        };

        List<DateTime> dateTimes = new List<DateTime>();

        foreach(string s in dateTimeStrings)
        {
            dateTimes.Add(DateTime.ParseExact(created_date, "yyyy-MM-ddThh:mm:ss", CultureInfo.InvariantCulture));
        }
    }
}