title: How to take automatically value from textbox
body: <p>I am trying to scan a card to a textbox and I want to take value from the textbox when the scanning complete.</p>
  
  <p>When I try this its execute before scan completion.</p>
  
  <pre><code>private void txtUserName_TextChanged(object sender, EventArgs e)
  {
      string val = txtUserName.Text;
  }
  </code></pre>