https://qooah.com/2012/03/20/%e5%8e%9f%e4%be%86%e5%bb%a3%e5%91%8a%e4%bd%94-android-app-%e7%9a%84-75-%e8%80%97%e9%9b%bb%e9%87%8f%ef%bc%8c%e9%9b%a3%e6%80%aa-android-%e6%a9%9f%e9%83%bd%e9%82%a3%e9%ba%bc%e8%80%97%e9%9b%bb/