asp.net c# how to handle null?

Question

I'm working on a project where I report Time Reports. Right now I am working on a feature where you can report vacation. From and to date. But when you just click the button send without having to enter anything in my two fields it will crash due null exception.

[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Index(DateTime fromDate, DateTime toDate, string comment)
{
    using (IDatabaseLayer db = new DatabaseLayer())
    {
        if (fromDate != null || toDate != null)
        {
            db.InsertVacation(Constants.CurrentUser(User.Identity.Name), fromDate, toDate, comment);
            ViewData.Model = db.GetUserVacations(Constants.CurrentUser(User.Identity.Name));
        }
    }

    SendVacationMail(fromDate, toDate, comment);
    ViewData["posted"] = true;

    return View();
}

When debugging it, it doesn't hit this code block unless my fields have values in them.

@codroipo But it dosen't even hit the block if my values are null. — foo bar
– foo bar, Commented Sep 24, 2015 at 12:44
@Sybren dosen't matter what operator I use, if my fields are null and I press submit it dosen't hit this block — foo bar
– foo bar, Commented Sep 24, 2015 at 12:44
even if the block isn't hit || is the wrong operator here if you want both values not to be null — Sybren
– Sybren, Commented Sep 24, 2015 at 12:45

ken2k · Accepted Answer · 2015-09-24 12:43:26Z

8

You probably just need your action to have nullable parameters:

public ActionResult Index(DateTime? fromDate, DateTime? toDate, string comment)
{
}

Do note a DateTime value cannot be null as it's a value type (it's a struct). You have to make it nullable, i.e. using Nullable<DateTime> or DateTime?.

answered Sep 24, 2015 at 12:43

ken2k

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3 Comments

foo bar Over a year ago

Right, I I should have though of that.. Thanks.

KarmaEDV Over a year ago

@foobar Why don't you mark the question as answered? Be nice, man!

foo bar Over a year ago

Because when e first posted it i tried and when it did work i were goong to accepterade it, but i could not accept it for 10 mins and i forgot. Hehe, thanks for reminding me.

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