说明：  在android开发中相信大家都会遇到这样的问题--android提供的控件没有你想要的！那么怎么办呢？这时你是否想要自己写一个完美匹配的空间来使用呢。这篇文档可以帮组你学习android中的自定义控件
(Android development believe that everyone will encounter this problem- the android to provide the control you want! So how should we do? Then if you want to write a perfect match for the space to use it. This document can help the group you learn android in the custom control)