title: how to check if the listView is empty
body: <p>Im creating a windows form and I have 2 problems </p>
  
  <ol>
  <li>I want to enable the button as soon as i add item in listView otherwise
  disable it if its empty</li>
  <li>assuming that i have already added item in listview. how can i get the totalprice of all the item and put it in the label as soon as the item added? thanks.</li>
  </ol>
  
  <p>this is the code is use to compute the total price of all item in the listview</p>
  
  <pre><code>    Dim total As Integer = 0
      For Each itemRow As ListViewItem In Me.lvOrder.Items
  
          total += Convert.ToInt32(itemRow.SubItems(2).Text)
  
      Next
  </code></pre>
  
  <p>sorry i cant put image for better understanding because i need 10 reputation to post an image.</p>