title: how to fix System.Windows.Forms.Control.ControlCollection' does not contain a definition for 'item'
body: <pre><code>((AxAcroPDFLib.AxAcroPDF)tabControl1.SelectedTab.Controls.item(0)).src = openPDF.FileName;
  </code></pre>
  
  <blockquote>
    <p>Error 1   'System.Windows.Forms.Control.ControlCollection' does not
    contain a definition for 'item' and no extension method 'item'
    accepting a first argument of type
    'System.Windows.Forms.Control.ControlCollection' could be found (are
    you missing a using directive or an assembly reference?)</p>
  </blockquote>
  
  <p>anybody know how to solve this?
  thanks for your help</p>