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copied!<p>The <code>LongListSelector</code> is using a <code>ScrollViewer</code> internally (apparently since the Aug 2011 release). This fact can be used to restore the position of the list after tombstoning by following the example given at <a href="http://damianblog.com/2011/01/21/wp7-scroll-pivot/" rel="nofollow">http://damianblog.com/2011/01/21/wp7-scroll-pivot/</a> for the pivot controller.</p> <p>In <code>OnNavigatedFrom()</code> remember the scroll offset:</p> <pre class="lang-cs prettyprint-override"><code> private bool _newPageInstance = true; private double _scollOffset = double.NaN; protected override void OnNavigatedFrom(System.Windows.Navigation.NavigationEventArgs e) { base.OnNavigatedFrom(e); var scrollViewer = FindScrollViewer(LongList); State["scrollViewer.VerticalOffset"] = scrollViewer.VerticalOffset; State["PreservingPageState"] = true; _newPageInstance = false; } private static ScrollViewer FindScrollViewer(DependencyObject parent) { var childCount = VisualTreeHelper.GetChildrenCount(parent); for (var i = 0; i < childCount; i++) { var elt = VisualTreeHelper.GetChild(parent, i); if (elt is ScrollViewer) return (ScrollViewer)elt; var result = FindScrollViewer(elt); if (result != null) return result; } return null; } </code></pre> <p>And restore it in <code>OnNavigatedTo()</code> if the app have been tombstoned:</p> <pre class="lang-cs prettyprint-override"><code> protected override void OnNavigatedTo(System.Windows.Navigation.NavigationEventArgs e) { base.OnNavigatedTo(e); if (!_newPageInstance || !State.ContainsKey("PreservingPageState")) { return; } _scollOffset = (double)State["scrollViewer.VerticalOffset"]; } private void LongList_Loaded(object sender, RoutedEventArgs e) { if (double.IsNaN(_scollOffset)) return; var longListSelector = (LongListSelector)sender; var scrollViewer = FindScrollViewer(longListSelector); scrollViewer.ScrollToVerticalOffset(_scollOffset); _scollOffset = double.NaN; } </code></pre>

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