title: Adding Null Value to ComboBox bound to ArrayList
body: <p>I've seen a few similar questions to this issue I'm having, but they all don't seem to work out.</p>
  
  <p>I currently have a method that populates an arraylist with items from a database query, and then returns the arraylist to be used to populate a ComboBox. The ComboBox will be used as a search filter for additional database queries. </p>
  
  <p>I'd like to add a null value to the arraylist in order to allow for the user to "turn the filter off" when the null value is selected.</p>
  
  <p>The issue comes up when adding the null value to the array list. When I add the null value before the database items are added, all of the items don't show up in the actual ComboBox. When I add the null value after the ArrayList has been populated, the null value never shows up as a row in the ComboBox, but everything else is there.</p>
  
  <pre><code>        public static ArrayList DropDown()
      {
          ArrayList status = new ArrayList();
          connect.Open();
  
          // Finds the stuff to use in the  COMBO BOX
          cmd.CommandText = String.Format("query");
          reader = cmd.ExecuteReader();
  
          while (reader.Read())
          {
  
              status.Add(String.Format("{0}", reader[BANK_ID]));
          }
          string holder = null;
          status.Add(holder); 
          connect.Close();
          return status;
      }
  </code></pre>
  
  <p>This results in the populated ComboBox, but no null row.</p>
  
  <pre><code>        public static ArrayList DropDown()
      {
          ArrayList status = new ArrayList();
          string holder = null;
          status.Add(holder); 
          connect.Open();
  
          // Finds the stuff to use in the  COMBO BOX
          cmd.CommandText = String.Format("query");
          reader = cmd.ExecuteReader();
          ;
          while (reader.Read())
          {
  
              status.Add(String.Format("{0}", reader[BANK_ID]));
          }
  
          connect.Close();
          return status;
      }
  </code></pre>
  
  <p>This results in nothing in the combo box.</p>
  
  <p>Thanks for the help!</p>