private void _content_Loaded(object sender, RoutedEventArgs e)
{
_scrollViewer = _content.GetScrollViewer();
if (_scrollViewer != null)
{
_scrollViewer.DirectManipulationStarted += ScrollViewer_DirectManipulationStarted;
_scrollViewer.DirectManipulationCompleted += ScrollViewer_DirectManipulationCompleted;
var border = (Border)VisualTreeHelper.GetChild(_scrollViewer, 0);
if (border == null)
{
_scrollViewer.Loaded += ScrollViewer_Loaded;
}
else
{
ScrollViewer_Loaded(this, null);
}
}
else
{
throw new InvalidOperationException("content's first child must be ScrollViewer");
}
}