title: displaying line number in rich text box c#
body: <p>I have a Multiline richtextbox control into which i want to integrate the feature of adding a line number. i have considered many approaches</p>
  
  <ol>
  <li>Add a label and updating the line numbers as the line count changes</li>
  <li>Add a picturebox along with to draw string on it.</li>
  <li>Add another textbox along with and show line numbers on it</li>
  <li>Add listbox along and display line numbers in it.</li>
  </ol>
  
  <p>I got two doubts.</p>
  
  <ol>
  <li>The richtextbox which i'm using is a custom made control and derieves from RichTextBox class. How can i add multiple controls to it.</li>
  <li>What is the best approach to show line numbers for the multiline text in c#</li>
  </ol>