Validating Date Conversion

I'm still a C Sharp rookie and I need a little help trying to implement the validation of a Convert.ToDateTime routine.

I have three text boxes on a form to capture MM, DD and YYYY. I've set up range validators on the form so that MM can only be between 1 and 12, DD between 1 and 31 and YYYY between 1900 and 2010. Ultimately the data is stored in the database in the decimal format of MMDDYY (legacy design that I can't change yet), but I want implement some further validation of the date (such as 02/29/2010 is not a valid date), so here was my stab at doing so.

if (admitDDTextBox.Text != "" & admitMMTextBox.Text != "" & admitYYYYTextBox.Text != "")
        {

            string admitStringDate = string.Concat(txtMMadmit, "/", txtDDadmit, "/", txtYYYYadmit);

            try
            {

                DateTime admitDateConverted = Convert.ToDateTime(admitStringDate);

            }

            catch (DataException ex)
            {
                lblError.Text = "Admit Date Not a Valid Date. Please Correct Admit Date and Resubmit";
            }
        }

When I try running this in debugger with invalid date input, it just stops at the Convert.ToDateTime, indicating there is an error in the date format string. With a valid date, the program just proceeds on as it normally should.

How can implement a check to determine if the date is valid and throw a message back to the user, using only C# to get it done?

Thanks for any/all help.

2 Replies

Know the answer? Post it — somebody with the same question will find it here.

Charbel Abdo16y ago
Accepted answer

DateTime myDate = new DateTime();
bool validDate = DateTime.TryParse(admitStringDate , out myDate);
try parse returns false if parsing fails,and put the result in the out variable (myDate)

Also, try replacing catch (dataException) with catch (exception) or catch (invalidCastException)

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Todd Burrell16y ago
Thank you, Charbel, for your reply. if worked. What I did after was:

if (validDate == false)
            {
                lblError.Text = "Admit Date Not a Valid Date. Please Correct Admit Date and Resubmit";
                return;
            }

and this seems to have worked fine, in limited testing.
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