推荐几个Resources连接
1、Drawable Resource简介
http://blog.csdn.net/lonelyroamer/article/details/8148147
2、BitmapDrawable和Bitmap
http://blog.csdn.net/lonelyroamer/article/details/8147542
3、NinePatchDrawable和NinePatch图片的制作
http://blog.csdn.net/lonelyroamer/article/details/8161958
4、LayerDrawable
http://blog.csdn.net/lonelyroamer/article/details/8162569
5、StateListDrawable