https://qooah.com/2010/12/19/%e5%82%b3%e8%81%9eandroid-2-4-honeycomb-%e5%b0%87%e6%96%bc%e6%98%8e%e5%b9%b4%e4%ba%8c%e6%9c%88%e5%85%ac%e4%bd%88/