????Activity?????????????

????Android?????????????(Multi-Task)?????????????????????????????????????????????????????????ó?????????Щ????棬??????е?????????????????????????????棬??????????????????????????

???????????????? Android ??????????μ????-- ????????(Life Cycle)??

????Android ??ó????????????????Android ?????й??????????????ó???????

??????????????????ó???(????????????Activity ??onCreate ????)?????????

???????????(Process)????????漴???????????????????????????н???(process)??????????????????????? ????????????ó?????????????????????????????????????????????????????????

????Activity?????????

?????3.1activity?????????

????Activity?????????????4??????7???????????3????????

????1> ??????

??????(Active/Running)??

??????Activity???????????(??????????????????)?????????????????????????????????????????????????????????Activity ?????(Active)??????

????(Running)??

???????(Paused)??

??????Activity???????????????(?????????????????????Activity??Toast??AlertDialog??????????)??????????????????Activity?????????(???????????е???????????????????????????????)???????????漫С???????????

????3. ??(Stopped)??

??????????????Activity????????????????????????????е???????????????????????????????????????????????????????