public static BlockCollection GetBlockCollection(FrameworkContentElement elem)
{
if (elem == null) return null;
var propInfo = elem.GetType().GetProperty("Blocks");
if (propInfo == null) return null;
if (propInfo.CanRead && propInfo.PropertyType==typeof(BlockCollection))
{
return propInfo.GetValue(elem, null) as BlockCollection;
}
if (elem is FlowDocument) return ((FlowDocument)elem).Blocks;
if (elem is Section) return ((Section)elem).Blocks;
if (elem is ListItem) return ((ListItem)elem).Blocks;
if (elem is TableCell) return ((TableCell)elem).Blocks;
return null;
}
