从类型集合中获取公共基类的最简单方法

I'm building a custom property grid that displays the properties of items in a collection. What I want to do is show only the properties in the grid that are common amongst each item. I am assuming the best way to do this would be to find the the common base class of each type in the collection and display it's properties. Is there any easier way? Can you give me a code example of the best approach to do this?I'm building a custom property grid that displa