Jaypar Android Introduction

ANDROID

ACTIVITY IN

@2015 Hoang Trung Hieu

Activity in AndroidKhi nim v Activity?Ngn xp Activity (Activity Stack)Vng i ca Activity (Activitys Life Cycle)NI DUNG CHNH

Activity in AndroidActivity l mt trong 4 thnh phn ca ng dng Android:ActivityIntent ReceiverServiceContent ProviderTrong , Activity l thnh phn thng c s dng nht.

ACTIVITY L G?

Khi nim Activity

Activity in AndroidActivity:Thng thng l mt Screen trong ng dngBao gm cc View v cc trnh p ng s kinHu ht, cc ng dng c nhiu Screen hay nhiu ActivityV d, ng dng thoi:Mt Screen hin th mn hnh quay sMt Screen hin th nht k cuc giMt Screen hin th cc lin lc

Khi nim Activity

Activity in AndroidMi Activity c mt vng i ring c lp hon ton vi cc Activity khc.Mt ng dng s bt u vi mt Actitity mainTrong class Activity s dng phng thc setContentView(View) hin th layout cho Screen.

Khi nim Activity

Activity in Android

Khi to Layout cho Activity

Activity in AndroidMi Activity c mt vng i ring c lp hon ton vi cc Activity khc.Mt ng dng s bt u vi mt Actitity mainMt ng dng s bt u vi mt Actitity mainTrong class Activity s dng phng thc setContentView(View) hin th layout cho Screen.Mi Activity mun c triu gi trong ng dng th n phi c khi bo cho file AndroidManifest.xml

Khi nim Activity

Activity in Android

Khi bo Activity trong AndroidManifest.xml

Activity in AndroidKhi nim v Activity?Ngn xp Activity (Activity Stack)Vng i ca Activity (Activitys Life Cycle)

Activity in Android

Activity Stack

Mi mt Activity mi c m ln n s bn trn Activity c, tr v Activity th bn ch cn nhn nt Back tr v hoc vit lnh. Tuy nhin nu bn nhn nt Home ri th s khng th dng nt Back quay li mn hnh c c. y bn ch l c 2 kiu m Activity mi :a) M Activity mi ln lm che khut ton b Activity c (khng nhn thy Activity c): sy ra s kinonPauserionStopi vi Activity cb) M Activity mi ln lm che khut mt phn Activity c (vn nhn thy Activity c): Sy ra s kinonPausevi Activity c. Khi quay tr v Activity c th sau khi thc hin xong cc hm cn thit, chc chn n phi gi hmonResume phc hi li trng thi ng dng Nh vy ta thng lu li trng thi ca ng dng trong s kinonPausev c li trng thi ng dng trong s kinonResume10

Activity in AndroidKhi nim v Activity?Ngn xp Activity (Activity Stack)Vng i ca Activity (Activitys Life Cycle)

Activity in AndroidMi Activity vng i thng c 3 trng thi sau:Running: ang kch hotPaused: tm dngStopped: dng khng phi

Activitys Life Cycle

Activity in Android

1-Running(ang kch hot): Khi mn hnh l Foreground ( Activity nm trn cng ng dng v cho php ngi s dng tng tc)2-Paused(tm dng) : Activity b mt focus nhng m vn nhn thy c Activity ny (V d bn m mt Activity mi ln di dng Dialog). Trng hp ny n vn c kh nng b h thng t ng X trong tnh hung b nh qu t.3-Stopped(dng khng phi Destroyed): Activity mt focus v khng nhn thy c (v d bn m mt Activity mi ln m Full mn hnh chng hn). Trong trng hp ny n c th b h thng X trong bt k tnh hung no.

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Activity in Android

Visible & Foreground LifeTime

Visible Lifetime:+ sy ra t sau khi gi onStart > cho ti lc gi onStop : trong trng hp ny TA vn c th thy mn hnh Activity (c th tng tc khi n l foreground, khng tng tc c khi n khng phi foreground nh gii thch trn)- Foreground Lifetime:+ Sy ra t khi gi onResume > cho ti lc gi onPause : trong sut thi gian ny Activity lun nm trn cng v Ta c th tng tc c vi n15

Thank you for listening!Any questions?