The best overloaded method match for int tryparse Error

Question

I'm simply trying to do this, so later on when I save my values in the database they should be set to null incase the textfield is empty.

    int? DeliveryAdrID = null;
    int.TryParse(TextBoxDeliveryAdrID.Text, out DeliveryAdrID);

But I'm having an error parsing it along.

The above solution should later on make it possible to save empty textbox values in the database as "NULL" instead of 0.

The whole solution:

    int parsedValue;
    int? DeliveryAdrID = int.TryParse(TextBoxDeliveryAdrID.Text, out parsedValue) ? parsedValue : (int?)null;

    int id = Convert.ToInt32(GridViewData.SelectedValue.ToString());
                var data = tf.DBTable.Where(a => a.ID == id).FirstOrDefault();
                if (data == null)
                {
                    DBTable mt = new DBTable();
                    mt.Customer = TextBoxCustomer.Text;
                    mt.Country = TextBoxCountry.Text;
                    mt.DeliveryAdrID = parsedValue;
                    tf.DBTable.AddObject(mt);
                    tf.SaveChanges();
                }
                else
                {
                    data.Customer = TextBoxCustomer.Text;
                    data.Country = TextBoxCountry.Text;
                    data.DeliveryAdrID = parsedValue;
                    tf.SaveChanges();
              }
            }

Answer 1

You cannot give a nullable int to int.TryParse. It must be an int. What you are trying to do can be accomplished like so:

int parsedValue;
int? DeliveryAdrID = int.TryParse(TextBoxDeliveryAdrID.Text, out parsedValue) ? parsedValue : (int?) null;