DateTime.TryParseExact fails

Question

I need a method that converts a string to a datetime. The format for the datetime must be dd/MM/yyyy If the string is in any other format, the method will return null.

This is wat I have so far :

    private DateTime? StringToDateTime(string value)
    {
        DateTime? Result = null;
        DateTime test = DateTime.Now.Date;
        if (DateTime.TryParseExact(value, "dd/MM/yyyy", System.Globalization.CultureInfo.InstalledUICulture, System.Globalization.DateTimeStyles.None, out test))
            Result = test;
        return Result;
    }

and to test it I use this

    private void button1_Click(object sender, EventArgs e)
    {
        string value = "01/01/2015";
        DateTime? test = StringToDateTime(value);
        if (test == null)
            MessageBox.Show("invalid date entered");
        else
            MessageBox.Show(test.ToString()); 
    }

Now the problem is that the TryParseExact always fails. I also tried "dd/mm/yyyy" as format, but with same results.

So I must be doing something wrong here. Does anybody has an example how to use DateTime.TryParseExact or is there another way of doing this ?

EDIT: This is not a duplicate since the "duplicate" link advises to use TryParseExact while my question is using this from the start and is asking why it does not work

Answer 1

Change your code to:

DateTime? Result = null;
DateTime test = DateTime.Now.Date;
if (DateTime.TryParseExact(value, "dd/MM/yyyy", System.Globalization.CultureInfo.InvariantCulture, System.Globalization.DateTimeStyles.None, out test))
    Result = test;

The change is to use CultureInfo.InvariantCulture instead of CultureInfo.InstalledUICulture .

Answer 2

For me the format was an issue, with the following code it accepts 01/01/2015 as well as 1/1/2015 ( dd/MM/yyyy and d/M/yyyy ):

DateTime? Result = null;
DateTime test = DateTime.Now.Date;
var formats = new[] { "dd/MM/yyyy", "d/M/yyyy" };
if (DateTime.TryParseExact(value, formats , System.Globalization.CultureInfo.InvariantCulture, System.Globalization.DateTimeStyles.None, out test))
    Result = test;