title: C# How to use treeView to list the directories and subdirectories without showing the root directory?
body: <p>From</p>
  
  <pre><code>main folder
  |_a
  | |_b
  | |_c
  |_d
  |_e
  </code></pre>
  
  <p>to</p>
  
  <pre><code>a
   |_b
   |_c
  d
  e
  </code></pre>
  
  <p>I want a treeview without the main folder. I found a solution <a href="https://stackoverflow.com/questions/21663060/how-to-use-treeview-to-list-the-files-within-sub-directories-without-showing-the">here</a> but it seems that it's incredibly slow. When I first start the program it takes over a minute to load it. Without that code it opens instantly.</p>
  
  <p>So, do you know any why to improve this code or another better code?</p>
  
  <p>EDIT: <strong>solved</strong>.</p>