title: Add items to combobox with multiple values C#
body: <p>currently I have a combobox with three hard coded items.
  Each item carries 2 values. I'm using a switch case statement to get the values for each item depending on which item is selected.</p>
  
  <pre><code>Switch(combobox.selectedindex)
  {
      case 0: // Item 1 in combobox
          a = 100;
          b = 0.1;
          break;
      case 1: // Item 2 in combobox
          a = 300;
          b = 0.5;
          break;
      //and so on....
  }
  </code></pre>
  
  <p>I'm trying to add a feature to allow the user to add more items into the combobox with inputted a and b values. How would i be able to dynamically add case statements and define the values under each case condition? I've had a look at using a datatable instead but I don't know how to get multiple valuemembers out of the datatable when one item is selected.</p>
  
  <p>Also, I would like to save the user added items and it's corresponding values to a .dat file. So when the program is re-opened it will be able to load the list of items added by the user from the file. I considered using streamwriter and readline for this but I'm unsure how it would be done.</p>