public override void OnNavigatedTo(NavigatedToEventArgs e, Dictionary <string, object> viewModelState)
{
var frame = Window.Current.Content as Frame;
_scrollView = VisualHelper.FindVisualChildInsideFrame <ScrollViewer>(frame);
_canvasControl = (CanvasControl)_scrollView.Content;
_strokes = new Stack <IDrawing>();
PenSize = 5;
PenColor = paletteColors[paletteColors.Count - 1];
CurrentDrawingMode = DrawingMode.Lines;
base.OnNavigatedTo(e, viewModelState);
}