https://qooah.com/2012/05/08/%e6%96%b0%e4%b8%80%e6%89%b9%e6%95%b8%e6%93%9a%e5%85%ac%e9%96%8b%ef%bc%8candroid-%e8%9f%ac%e8%81%af%e7%be%8e%e5%9c%8b%e7%ac%ac%e4%b8%80%e6%99%ba%e8%83%bd%e7%b3%bb%e7%b5%b1/