文档介绍：毕业设计android毕业论文英文翻译
毕业设计android毕业论文英文翻译
毕业设计android毕业论文英文翻译
Apｐｌicaｔｉon Funｄameｎｔaｌs
Andrｏiｄ ａpplications ａｒe writｔeｎ in ｔhe Jaｖa prｏgrammｉｎg lａnguａgｅ。 Thｅ cｏmpｉled Java ｃode — along with any dａtａ ａnd resｏurcｅ ｆiles reｑuiｒed ｂy thｅ appｌication — ｉs ｂundleｄ by the aaｐt tool ｉnto an Ａndｒoid packａge， an aｒchｉvｅ bｙ an 。apk suffix。 Tｈｉｓ tｈｅ vehicｌｅ foｒ dｉstriｂuｔｉｎｇ thｅ apｐｌicａtion ａｎd ｉnstaｌliｎg ｉt on ｍｏbｉle deviｃeｓ; ｉt＇s the downlｏad to ｔhｅｉｒ ｄeｖiceｓ. Ａlｌ thｅ coｄe in ａ sｉｎgle 。apk considｅｒed ｔo be ｏne apｐlicatｉon。
In ｍaｎy wayｓ， eacｈ Ａｎｄrｏid ａppliｃaｔion liｖeｓ in its oｗn woｒlｄ:
1. By ｄｅfａuｌt， ｅvery appliｃaｔiｏn ｒuns ｉn iｔs own Ｌinuｘ pｒocess。 Androiｄ staｒts ｔｈe procesｓ wｈen any ｏf the applicaｔｉon's coｄe needs to be executed， ａｎd shuts doｗn thｅ procｅｓs when it's no ｌongeｒ neeｄｅd anｄ sｙsｔem resouｒces ａrｅ requirｅd ｂy other aｐｐlicatｉonｓ.
2。 Ｅaｃh pｒｏcess has its own viｒtual machine (ＶＭ)， ｓo aｐpliｃaｔiｏｎ codｅ runｓ in isｏlation frｏm ｔhe code of alｌ otｈer aｐplicatｉonｓ．
3. By ｄefault， ｅach aｐplicatiｏn is asｓｉｇｎed a uniqｕe Ｌiｎux uｓer ID。 Permiｓsｉｏｎs are set so thaｔ tｈe apｐlｉｃation’s files are vｉsible onｌy to ｔhａt uｓer ａnｄ onlｙ ｔo the applｉcａtion itsｅlf — ａltｈough ｔheｒｅ aｒe ways ｔo eｘｐort tｈeｍ ｔo oｔｈｅr applｉcatioｎs as wｅlｌ。
Iｔ’s ｐｏssible to ａｒrangｅ fｏｒ ｔwo applicatiｏｎs to ｓhａre tｈe ｓａme useｒ ID, ｉn whｉcｈ ｃase they ｗｉll be aｂｌe to see eacｈ ｏtheｒ’s fｉlｅs． Ｔo conserve ｓysteｍ resｏuｒces， appｌications witｈ the ｓaｍe IＤ can also ａrrange to rｕn ｉn tｈe saｍe Ｌｉｎux proceｓs， sｈａring the same VM.
Appｌｉcatｉon Ｃｏmｐonents
Ａ cｅntｒal featuｒe ｏf Anｄrｏiｄ ｉs tｈａt ｏne ａｐplｉcation cａn make uｓe of elemeｎｔs ｏf oｔｈer applｉcａtionｓ (provided thosｅ applications pｅrmｉt ｉt）． Ｆor eｘａmple, if yoｕｒ ａｐplication needs ｔo ｄispｌaｙ a scrollinｇ list of images ａnｄ ａnothｅr apｐlｉcaｔion has ｄｅvｅloｐed a ｓuitabｌe scｒoller anｄ ｍａde it ａvaiｌaｂｌe tｏ otheｒs， you can ｃaｌl upｏn that scrｏller to do ｔhe wｏrk, ｒaｔher tｈan devｅｌｏp ｙour own． Ｙour appｌｉｃatiｏn ｄoesn'ｔ incoｒporａtｅ ｔhe code of the other applicaｔｉｏn or lｉnk ｔｏ ｉt。 Ｒ