title: add only items which contains specific text in textbox
body: <pre><code>string[] dirs = System.IO.Directory.GetDirectories(@"C:\Somefolder\");
  
  foreach (string dir in dirs)
  {
      listBox1.Items.Add(Path.GetFileName(dir));
  }
  </code></pre>
  
  <p>This is my code, and I have no idea how to get ONLY directories which contains name of something in my textbox for example. I have seen that someone had textbox, next to it button update, I tried to do it the same way - you write into textbox name of a folder ex. Windows and it shows ONLY the one folder so if I write Sys it will find System32 and SYSWOW64 &amp;&amp; it wont be case sensitive cause I can do simple if condition, but cant make it not case sensitive you know what I mean? my english is pretty bad, had to tell it this way hope its understandable</p>