title: c# ".datasource" not showing in the box
body: <p>Whenever I type the <code>.DataSource</code> it keeps having red on the bottom or having an error:</p>
  
  <blockquote>
    <p>'ListView' does not contain a defenition for 'DataSource' and no extension method 'DataSource' accepting a first argument of type 'ListView' could be found (are you missing a using directive or an assembly reference?)</p>
  </blockquote>
  
  <pre><code>public Form4()
  {
      InitializeComponent();
  
      lstProductsChosen.DataSource = products;
  }
  </code></pre>
  
  <p>What should I do? Do I need to add reference?</p>