title: Fire an event after Richtextbox Textchanged event
body: <p>I am writing a lexer and i also want my text editor to change the color of the keywords. While typing! like VS and ... ! but the problem is TextChanged event of a RichTextBox fires BEFOR adding the text to it. </p>
  
  <p>Is there any pre defined event that fire write AFTER adding the text to the richTextBox ? if not how can i create one that fire write after entering the text! </p>
  
  <p>PS : i am writing a WPF project! </p>
  
  <pre><code>private void rtxMain_TextChanged (object sender, TextChangedEventsArgs e) {
     visual.getLastWord();
  }
  </code></pre>