DateTime.TryParseExact() rejecting valid formats

Question

I'm parsing a DateTime value in an ASP.NET WebForms page and the date string keeps getting rejected by the DateTime.TryParseExact() method even though it clearly matches one of the supplied format strings.

It seems to fail on my development machine at home but work on the production server, so I am thinking of local date settings being involved, but this error occurs even when I supply an IFormatProvider (CultureInfo) object as a parameter

Here's the code:

DateTime startDate;
string[] formats = { "dd/MM/yyyy", "dd/M/yyyy", "d/M/yyyy", "d/MM/yyyy",
                    "dd/MM/yy", "dd/M/yy", "d/M/yy", "d/MM/yy"};

var errStart = row.FindControl("errStartDate"); //my date format error message
if (!DateTime.TryParseExact(txtStartDate.Text, formats, null, DateTimeStyles.None, out startDate))
{
    errStart.Visible = true; //we get here even with a string like "20/08/2012"
    return false;
}
else
{
    errStart.Visible = false;
}

Note I'm giving a null FormatProvider in the above, but the same problem occurs when I provide a CultureInfo object as (CultureInfo provider = new CultureInfo("en-US")) for this parameter.

What am I missing?

Answer 1

Try:

 DateTime.TryParseExact(txtStartDate.Text, formats, 
        System.Globalization.CultureInfo.InvariantCulture,
        System.Globalization.DateTimeStyles.None, out startDate)