WPF-InkCanvas undo operation after performing inkCanvas1.Strokes.Erase()

Question

I have a below code

private void inkCanvas1_OnTouchMove(object sender, TouchEventArgs touchEventArgs)
{
    StylusShape EraseShape = (StylusShape)new RectangleStylusShape(20, 20, 0);
    List<Point> enumrator = new List<Point>();
    TouchPoint touchPoint = touchEventArgs.GetTouchPoint(this);

    enumrator.Add(new Point(touchPoint.Position.X, touchPoint.Position.Y));
    inkCanvas1.Strokes.Erase(enumrator, EraseShape);//**reverse operation of this statement**
}

and I want to reverse back erased strokes after performing undo operation.

I have tried below event code. but when i erase multiple strokes then this logic is not performing well.

System.Windows.Ink.StrokeCollection addedStrokes;
System.Windows.Ink.StrokeCollection removedStrokes;
bool undoRedoInProcess = false;

private void Strokes_StrokesChanged(object sender, System.Windows.Ink.StrokeCollectionChangedEventArgs e)
{
    if (undoRedoInProcess)
    {
       addedStrokes = e.Added;
       removedStrokes = e.Removed;
    }       
}


private void Undo()
{
    undoRedoInProcess = true;
    inkCanvas1.Strokes.Remove(removedStrokes);
    inkCanvas1.Strokes.Add(addedStrokes);
    undoRedoInProcess = false;
}
private void Redo()
{
    undoRedoInProcess = true;
    inkCanvas1.Strokes.Add(addedStrokes);
    inkCanvas1.Strokes.Remove(removedStrokes);
    undoRedoInProcess = false;
}