http://gityuan.com/android/
http://gityuan.com/2016/03/12/start-activity/
https://blog.csdn.net/suifeng3051/article/details/52611310
https://blog.csdn.net/mwq384807683?viewmode=contents
https://blog.csdn.net/mwq384807683/article/details/72573616
https://blog.csdn.net/mwq384807683/article/details/71598790
原文：https://www.cnblogs.com/jooy/p/9306418.html