title: setting VerticalScrollingOffset programmatically
body: <p>I'm using a custom scroll bar and the problem I'm facing now is that when I have thousands of rows in a datagrid and scroll all the way to the bottom, <code>dataGrid.VerticalScrollingOffset</code> is about + 400 higher thank <code>customScrollbar.Value</code>. Which ends up with dataGrid now showing last few records, because it hasn't scrolled down enough.</p>
  
  <p>It would be perfect if I could set <code>dataGrid.VerticalScrollingOffset</code> value or get the maximum vertical scrolling value of dataGrid, I couldn't find any information on nether. </p>
  
  <p>Currently I'm calculating the maximum value like <code>rowCount*rowHeight</code>, which doesn't give exact max value, therefore it's not scrolling down all the way. Any suggestions? Thanks!</p>