CODEWITHSUNDEEP
c#asp.net
Nick Rodriquez
Nick Rodriquez

Reputation: 3

Object reference not set to an instance of an object Message with String Array

I have the following code:

protected void btnSave_Click(object sender, EventArgs e)
{
    StarBusModel.BookingDetail1 objBooking = new StarBusModel.BookingDetail1();
    objBooking.TourID = tourID;
    objBooking.Name = txtName.Text;
    objBooking.Phone = txtPhone.Text;
    objBooking.Amount = Convert.ToDecimal(Request.Form[txtAmount.ClientID]);


    string []  seats = Request.Form[txtSeatNo.ClientID].Split(new char[] {','});
    for (int i = 0; i < seats.Length; i++)
            objBooking.SeatDetails.Add(new StarBusModel.SeatDetail1() {SeatID = Convert.ToInt32(seats[i])});
    objEntities.BookingDetail1.AddObject(objBooking);        
    objEntities.SaveChanges();
    BindSeats();
}

I get the error

System.NullReferenceException: Object reference not set to an instance of an object.

at the following code:

string []  seats = Request.Form[txtSeatNo.ClientID].Split(new char[] {','});

Please advise where I am wrong. I searched for various answers but cannot pinpoint where I am wrong.

Upvotes: 0

Views: 2357

Answers (2)

Coofucoo
Coofucoo

Reputation: 119

NullReferenceException is a very headache excpetion. Even though you can know the line where the exception happen by see the stacktrace. But it may also include more than 1 possibilities.

Your case is an example.

string []  seats = Request.Form[txtSeatNo.ClientID].Split(new char[] {','});

In fact in this line, there are 2 place can cause null exception. They are:

  1. txtSeatNo.ClientID
  2. Request.Form[txtSeatNo.ClientID]

Normally the second is most possible.

So it is better to write the code in multiple lines and check the value before you use it. I think Jacob Abrahams gave a very good example.

Upvotes: 0

Jacob
Jacob

Reputation: 995

Request.Form[txtSeatNo.ClientID] is clearly null. In general, a NameValueCollection (like Request.Form) will return a null string if the given key is not defined.

You should do a check:

string seatString = Request.Form[txtSeatNo.ClientID];
string [] seats = String.IsNullOrEmpty(seatString) ? new char[]{} :
     seatString.Split(new char[] {','});

Upvotes: 2

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