DateTime.TryParse doesn't accept nullable DateTime?

Question

so I have this nullable variable I created:

private DateTime? _startDate;

I wanted to parse some variable to DateTime and then assign it to this variable, but the VS complains that the TryParse method has some invalid arguments.

if (string.IsNullOrEmpty(Request.Form["StartDate"]) == false)
        {
            DateTime.TryParse(Request.Form["StartDate"], out _startDate);
        }
        else
        { _startDate = null; }

Is there a syntax error I have or I can't use nullable variables in here?

Answer 1

As others have said, they're not compatible types. I would suggest you create a new method which wraps DateTime.TryParse and returns a Nullable<DateTime>:

// Add appropriate overloads to match TryParse and TryParseExact
public static DateTime? TryParseNullableDateTime(string text)
{
    DateTime value;
    return DateTime.TryParse(text, out value) ? value : (DateTime?) null;
}

Then you can just use:

_startDate = Helpers.TryParseNullableDateTime(Request.Form["StartDate"]);

(No need to check for null or empty string; TryParse will just return false in that case anyway.)