versions/nougat/android-7.0.jd

page.title=Android N cho Nh pht trin
meta.tags="preview", "androidn"
page.tags="preview", "developer preview"
page.image=images/cards/card-n-apis_2x.png
@jd:body


<div id="tb-wrapper">
<div id="tb">
  <h2>Cc tnh nng chnh cho nh pht trin</h2>
  <ol>
      <ul style="list-style-type:none;">
        <li><a href="#multi-window_support">H tr a ca s</a></li>
        <li><a href="#notification_enhancements">Thng bo</a></li>
        <li><a href="#jit_aot">Bin dch JIT/AOT</a></li>
        <li><a href="#quick_path_to_app_install">Ci t ng dng nhanh chng</a></li>
        <li><a href="#doze_on_the_go">Ch  Ng su khi di chuyn</a></li>
        <li><a href="#background_optimizations">Ti u ha chy ngm</a></li>
        <li><a href="#data_saver">Tit kim d liu</a></li>
        <li><a href="#tile_api">API cho  Ci t nhanh</a></li>
        <li><a href="#number-blocking">Chn s</a></li>
        <li><a href="#call_screening">Sng lc cuc gi</a></li>
        <li><a href="#multi-locale_languages">Bn a v ngn ng</a></li>
        <li><a href="#icu4">API ICU4J trong Android</a></li>
        <li><a href="#gles_32">API OpenGL ES 3.2</a></li>
        <li><a href="#android_tv_recording">Ghi li trn Android TV</a></li>
        <li><a href="#android_for_work">Android cho Cng vic</a></li>
        <li><a href="#accessibility_enhancements">Tr nng</a></li>
        <li><a href="#direct_boot">Khi ng Trc tip</a></li>
        <li><a href="#key_attestation">Chng thc kha</a></li>
        <li><a href="#network_security_config">Cu hnh Bo mt mng</a></li>
        <li><a href="#default_trusted_ca">CA an ton mc nh</a></li>
        <li><a href="apk_signature_v2">Lc  ch k s v2 cho tp APK</a></li>
        <li><a href="#scoped_directory_access">Truy cp th mc theo phm vi</a></li>
      </ol>
</div>
</div>


<p>Android N vn ang trong qu trnh pht trin nhng by gi bn c th dng th
di dng N Developer Preview. Cc phn di y s nu bt mt s
tnh nng mi cho nh pht trin. </p>

<p>
  Bn cn xem <a href="{@docRoot}preview/behavior-changes.html">Cc thay i Hnh vi</a>  bit c
  nhng phn thay i ca nn tng c th nh hng n ng dng ca bn, hy xem
  cc hng dn cho nh pht trin  bit thm v nhng tnh nng chnh v ti xung ti liu <a href="{@docRoot}preview/setup-sdk.html#docs-dl">Tham kho API</a>  bit chi tit v
  cc API mi.
</p>

<h2 id="multi-window_support">H tr a ca s</h2>


<p>Trong Android N, chng ti s a vo nn tng mt tnh nng a nhim mi
 rt c mong i &mdash; h tr a ca s. </p>

  <p>Gi y ngi dng c th nhanh chng m ng thi hai ng dng trn mn hnh. </p>
  <ul>
  <li>Trn in thoi v my tnh bng
chy Android N, ngi dng c th chy hai ng dng song song hai bn hoc
  trn di trong ch  chia i mn hnh. Ngi dng c th thay i kch thc ca ng dng bng cch ko
thanh phn chia  gia. </li>

<li>Trn thit b Android TV, cc ng dng c th t t vo <a href="{@docRoot}preview/features/picture-in-picture.html">ch
hnh-trong-hnh</a>, cho php ng dng tip tc hin th ni dung khi ngi dng duyt web hoc
tng tc vi ng dng khc. Hy xem bn di  bit thm thng tin. </li>
  </ul>

<div class="col-4of10">
<img src="{@docRoot}images/android-7.0/mw-portrait.png" alt="" style="height:460px;padding-left:1em;" id="img-split-screen" />
<p class="img-caption">
  <strong>Hnh 1.</strong> Cc ng dng chy trong ch  chia mn hnh.
</p>
  </div>

<p>c bit l trn my tnh bng v cc thit b mn hnh ln khc, vic h tr a ca s
cho php bn mang li nhng cch thc mi thu ht ngi dng. Thm ch bn cn c th cho php ko th trong
ng dng  ngi dng ko ni dung mt cch thun tin vo hoc ra ngoi ng dng ca bn &mdash; y l mt cch
nng cao tri nghim ca ngi dng rt hiu qu. </p>

<p>Thm tnh nng h tr a mn hnh vo ng dng ca bn v cu hnh cch thc
x l hin th a ca s l iu rt n gin. V d, bn c th ch nh kch thc
ti thiu cho php ca hot ng, ngn ngi dng thay i kch thc ca hot ng nh hn
kch thc . Bn cng c th v hiu ha hin th a ca s cho ng dng ca mnh, gip
  m bo h thng s ch hin th ng dng ca bn  ch  ton mn hnh.</p>

<p>
   bit thm thng tin, hy xem ti liu cho nh pht trin <a href="{@docRoot}preview/features/multi-window.html">H tr a ca s</a>
.
</p>

<h2 id="notification_enhancements">Ci tin thng bo</h2>

<p>Chng ti  thit k li thng bo trong Android N  chng c s dng d dng v nhanh
hn. Mt s cc thay i bao gm:</p>

<ul>
  <li>
    <strong>Cp nht Mu</strong>: Chng ti  cp nht cc mu thng bo
  to im nhn mi cho nh gy n tng v nh i din. Nh pht trin s c th
   tn dng cc mu mi nhng ch cn thc hin mt s chnh sa nh trong m ngun ca h.
  </li>

  <li>
    <strong>Thng bo gp</strong>: H thng c th nhm cc tin nhn
  li vi nhau, v d nh theo ch  tin nhn v hin th thnh nhm. Ngi dng c th
   thc hin cc thao tc nh Hy hoc Lu tr chng ngay ti ch. Nu bn tng
   trin khai cc thng bo cho Android Wear th bn  lm quen vi
   m hnh ny.
  </li>

  <li>
    <strong>Tr li trc tip</strong>: i vi nhng ng dng giao tip theo thi gian thc,
   h thng Android s h tr tr li ngay ti ch  ngi dng c th nhanh chng phn hi li
   mt tin nhn SMS hoc tin nhn vn bn trc tip bn trong giao din thng bo .
  </li>

  <li>
    <strong>Dng xem ty chnh</strong>: Hai API mi cho php bn s dng cc trang tr
   h thng nh tiu  v hnh ng ca thng bo khi s dng cc dng xem
   ty chnh trong thng bo.
  </li>
</ul>

<div class="col-4of12">
  <img src="{@docRoot}images/android-7.0/notifications-1.png" alt="" style="padding:.5em;max-width:226px">
</div>

<div class="col-4of12">
  <img src="{@docRoot}images/android-7.0/notifications-3.png" alt="" style="padding:.5em;max-width:226px">
</div>

<div class="col-4of12">
  <img src="{@docRoot}images/android-7.0/notifications-2.png" alt="" style="padding:.5em;max-width:226px">
</div>


<p class="img-caption">
  <strong>Hnh 2.</strong> Thng bo gp v tr li trc tip.
</p>

<p>Hy xem
  hng dn v <a href="{@docRoot}preview/features/notification-updates.html">Thng bo</a>
  bit cch trin khai cc tnh nng mi ny.</p>


<h2 id="jit_aot">Bin dch JIT/AOT theo cu hnh</h2>

<p>Trong Android N, chng ti  b sung mt trnh bin dch Just in Time (JIT) c m c cu hnh cho
ART, cho php n nng cao hiu nng ca cc ng dng Android tc th khi
chy. Trnh bin dch JIT b tr thm cho trnh bin dch Ahead of Time (AOT) ca ART
v gip ci hin hiu nng thi gian chy, tit kim khng gian lu tr v tng tc  cc bn cp nht ca
ng dng v cp nht ca h thng.</p>

<p>Bin dch theo cu hnh cho php ART qun l qu trnh bin dch AOT/JIT ca tng ng dng
ty theo s dng thc t cng nh cc iu kin trn thit b. V
d, ART s duy tr mt cu hnh cho cc phng thc hay dng nht ca mi ng dng v c th bin dch trc
ri to b m cho cc phng thc   c hiu nng cao nht. Nhng phn khc ca ng dng
s c gi nguyn khng bin dch cho n khi chng thc s c s dng.</p>

<p>Bn cnh nng cao hiu nng cho cc phn chnh ca ng dng, qu trnh bin dch
theo cu hnh cn gip gim tng lng RAM c s dng ca ng dng, bao gm c cc
tp nh phn lin quan. Tnh nng ny c bit quan trng trn cc thit b t b nh.</p>

<p>ART s qun l qu trnh bin dch theo cu hnh bng cch gim ti thiu tc ng n
pin ca thit b. N s tin hnh qu trnh bin dch trc ch khi no thit b nhn ri v
ang sc, gip tit kim thi gian v pin bng cch thc hin cng vic  trc.</p>

<h2 id="quick_path_to_app_install">Ci t ng dng nhanh chng</h2>

<p>Mt trong nhng li ch d thy nht ca trnh bin dch JIT ca ART l tc  ci t
ng dng v cp nht h thng. Ngay c cc ng dng ln cn vi pht
ti u v ci t trong Android 6.0 th gi y c th ci t ch trong mt vi
giy. Cc cp nht cho h thng cng s nhanh hn v khng cn bc ti u ha na. </p>

<h2 id="doze_on_the_go">Ch  Ng su khi di chuyn...</h2>

<p>Ch  Ng su  c gii thiu trong Android 6.0. y l mt ch  ca h thng gip tit kim pin bng cch tr hon
cc hot ng CPU v mng ca ng dng khi thit b ang nhn ri, v d nh khi thit b
ang nm trn bn hoc trong ngn ko. </p>

<p>Gi y Ch  Ng su trong Android N  c ci tin thm v tit kim pin ngay c khi ang di chuyn.
Bt k khi no mn hnh ang tt trong mt khong thi gian v thit b khng c cm sc th
Ch  Ng su s p dng tp con ca cc hn ch CPU v mng quen thuc i vi cc ng dng.
iu ny c ngha l ngi dng c th tit kim pin ngay c khi ang mang thit b trong ti
ca h.</p>


<img src="/preview/images/doze-diagram-1.png" alt="" id="figure1" />
<p class="img-caption">
  <strong>Hnh 3.</strong> Ch  Ng su ang p dng
   cc hn ch  ci thin thi lng pin ngay c khi thit b khng c t mt ch.
</p>


<p>Sau mt khong thi gian ngn khi mn hnh tt v thit b ch chy bng ngun pin, Ch  Ng su
s hn ch truy cp mng v tr hon cc tc v, ng b. Trong cc khong thi gian
bo tr ngn, cc ng dng s c php truy cp mng v mi tc v/ng b
b tr hon s c thc thi. Bt mn hnh hoc cm sc vo thit b s a
thit b thot khi Ch  Ng su.</p>

<p>Khi  thit b nm mt ch ln na vi mn hnh c tt v chy bng pin trong mt
khong thi gian th Ch  Ng su s p dng ton b cc hn ch CPU v mng i vi {@link
android.os.PowerManager.WakeLock}, bo thc {@link android.app.AlarmManager} v qut
GPS/Wi-Fi.</p>

<p>Bn c th p dng cc thc hnh tt nht tng t  iu chnh ng dng ca mnh cho Ch  Ng su cho d
thit b c ang di chuyn hay ng yn. Do , nu bn  cp nht ng dng  x l
Ch  Ng su mt cch tinh t th bn hon ton yn tm. Nu khng, hy tin hnh <a href="{@docRoot}training/monitoring-device-state/doze-standby.html#assessing_your_app">lm cho
 ng dng thch ng vi Ch  Ng su</a> ngay.</p>

<h2 id="background_optimizations">D n Svelte: Ti u ha chy ngm</h2>

<p>D n Svelte l mt n lc lin tc nhm ti gim s dng RAM ca h thng v cc ng dng
trn khp h sinh thi cc thit b Android. Trong Android N, d n
Svelte tp trung vo vic ti u ha cch thc cc ng dng chy ngm. </p>

<p>X l chy ngm l mt phn quan trng ca hu ht cc ng dng. Khi s dng ng cch, n
c th gip cho tri nghim ngi dng ca bn tr nn tuyt vi &mdash; tc th, nhanh chng v nhn bit c bi cnh.
Khi khng s dng ng cch, x l chy ngm c th tiu tn RAM (v
pin) mt cch khng cn thit cng nh nh hng n hiu nng h thng cho cc ng dng khc. </p>

<p>K t Android 5.0, {@link android.app.job.JobScheduler}  tr thnh
cch thc c u tin  thc hin cng vic chy ngm thch hp
cho ngi dng. ng dng c th ln lch cho cc tc v trong khi cho php h thng ti u ha da trn
cc iu kin v b nh, ngun in v kt ni. JobScheduler em li kh nng kim sot v
s n gin, v chng ti mun mi ng dng u s dng n. </p>

<p>
  Mt gii php hiu qu khc l <a href="https://developers.google.com/android/reference/com/google/android/gms/gcm/GcmNetworkManager">
  <code>GCMNetworkManager</code></a>, thuc mt phn ca Dch v Google Play, cho php
 ln lch tc v tng t vi kh nng tng thch trn cc phin bn Android
  c.
</p>

<p>Chng ti ang tip tc k tha <code>JobScheduler</code> v
<code>GCMNetworkManager</code>  p ng nhiu hn
cc trng hp s dng ca bn &mdash; v d nh trong Android N gi y bn  c th ln lch cho cng vic
chy ngm da vo nhng thay i trong cc Trnh cung cp Ni dung. ng thi, chng ti ang tin hnh
loi b mt s mu c c th lm gim hiu nng h thng,
c bit trn cc thit b t b nh.</p>

<p>Trong Android N, chng ti s loi b ba truyn pht khng biu th c s dng ph bin &mdash;
{@link android.net.ConnectivityManager#CONNECTIVITY_ACTION}, {@link
  android.hardware.Camera#ACTION_NEW_PICTURE} v {@link
  android.hardware.Camera#ACTION_NEW_VIDEO} &mdash; bi v cc truyn pht ny c th nh thc
cc tin trnh chy ngm ca nhiu ng dng cng lc v s dng qu mc b nh v pin. Nu
ng dng ca bn ang nhn cc truyn pht ny th hy tn dng N Developer Preview
  chuyn sang <code>JobScheduler</code> v cc API lin quan khc thay th. </p>

<p>
  Hy xem ti liu <a href="{@docRoot}preview/features/background-optimization.html">Ti u ha
 Chy ngm</a>  bit thm chi tit.
</p>


<h2 id="data_saver">Tit kim d liu</h2>

<div class="col-5of12" style="margin-right:1.5em;">
<img src="{@docRoot}images/android-7.0/datasaver.png" style="border:2px solid #ddd">

<p class="img-caption" style="padding-right:2em;">
  <strong>Hnh 4.</strong> Tnh nng Tit kim d liu trong mc Settings.
</p>
  </div>

<p>Trong vng i ca mt thit b di ng th chi ph gi cc d liu di ng v c bn
s cao hn gi thnh ca chnh thit b . i vi nhiu ngi dng, d liu di ng l mt
ti nguyn t  h mun s dng tit kim. </p>

<p>Android N  a vo ch  Tit kim d liu, mt dch v h thng mi gip gim
s dng d liu di ng, cho d l chuyn vng, gn n k thanh ton cc,
hoc trn mt gi d liu tr trc khim tn. Tit kim d liu cho ngi dng kim sot cch thc ng dng
s dng d liu di ng v cho php nh pht trin cung cp dch v hiu qu hn khi Tit kim
d liu c bt. </p>

<p>Khi ngi dng bt Tit kim d liu trong <strong>Settings</strong> v thit b ang
s dng mt mng c o lu lng th h thng s chn vic s dng d liu chy ngm v truyn tn hiu cho ng dng
 s dng t d liu hn  tin cnh bt c khi no c th &mdash; chng hn nh bng cch gii hn
bit rate  truyn pht, gim cht lng hnh nh, tr hon to trc b m  ti u,
v.v. Ngi dng c th lp danh sch cc ng dng c th c php s dng
d liu c tnh lu lng c chy ngm ngay c khi Tit kim d liu c bt.</p>

<p>Android N m rng lp {@link android.net.ConnectivityManager}  cung cp cho cc ng dng mt
cch thc <a href="{@docRoot}preview/features/data-saver.html#status">truy xut
cc ty chn Tit kim d liu ca ngi dng</a> v <a href="{@docRoot}preview/features/data-saver.html#monitor-changes">theo di
cc thay i ca ty chn</a>. Mi ng dng cn kim tra xem ngi dng   bt Tit kim
D liu hay cha v c gng gii hn s dng d liu chy  tin cnh v chy ngm.</p>


<h2 id="tile_api">API cho  Ci t nhanh</h2>


<div style="float:right;max-width:320px">
<img src="{@docRoot}images/android-7.0/quicksettings.png" style="padding-left:1.5em;">

<p class="img-caption" style="padding-left:2em;">
  <strong>Hnh 5.</strong> Cc  Ci t nhanh trong vng hin th thng bo.
</p>


  </div><p>Ci t nhanh l mt cch ph bin v n gin  hin th cc ci t v hnh ng quan trng,
trc tip t khu vc thng bo. Trong Android N, chng ti  m rng phm vi ca
Ci t nhanh  khin n tr nn hu ch v thun tin hn na. </p>

<p>Chng ti  thm khng gian cho cc  Ci t nhanh m ngi dng c th
truy cp trn ton b mt vng hin th c phn trang bng cch vut sang tri hoc phi. Chng ti cng
cho ngi dng kim sot nhng  Ci t nhanh no s xut hin v v tr xut hin
ca chng &mdash; ngi dng ch cn ko v th  thm hoc di chuyn cc . </p>

<p>i vi nh pht trin, Android N cng b sung mt API mi cho php nh ngha cc
  Ci t nhanh ca ring bn gip ngi dng d dng truy cp ti cc iu khin v hnh ng quan trng trong ng dng ca bn.</p>

<p>
  Cc  Ci t nhanh c dnh ring cho cc iu khin hoc hnh ng
   khn cp hoc thng xuyn c s dng, khng nn dng lm li tt
   khi chy mt ng dng.
</p>

<p>
  Mt khi  nh ngha cc  ca mnh bn c th lm ni chng ln trc ngi dng  h c th thm
  cc  ny vo Ci t nhanh bng cch ch cn ko v th.
</p>

<p>
   bit thm thng tin v vic to mt  ng dng, hy xem
  <code>android.service.quicksettings.Tile</code> trong ti liu <a href="{@docRoot}preview/setup-sdk.html#docs-dl">Tham kho API</a> c th ti xung.
</p>


<h2 id="number-blocking">Chn s</h2>

<p>Android N  h tr chn s in thoi trong nn tng ny v cung cp mt
 API khun kh cho php cc nh cung cp dch v duy tr mt danh sch s b chn.
ng dng SMS mc nh, ng dng gi in mc nh v cc ng dng ca nh cung cp c th c v
ghi vo danh sch s b chn. Cc ng dng khc khng th truy cp vo danh sch ny.</p>

<p>Thng qua vic a chn s thnh mt tnh nng tiu chun ca nn tng, Android s cung cp
cch thc thng nht  cc ng dng h tr chn s trn mt lot cc
thit b. Nhng li ch m ng dng c th tn dng gm:</p>

<ul>
  <li> S b chn cuc gi cng s b chn tin nhn vn bn
  <li> S b chn c th c duy tr qua cc ln thit lp li v qua nhiu thit b thng qua tnh nng Sao lu &amp;
Khi phc
  <li> Nhiu ng dng c th s dng cng mt danh sch s b chn
</ul>

<p>Ngoi ra, vic tch hp ng dng ca nh mng thng qua Android cng ng ngha l cc nh mng c th
c danh sch s b chn trn thit b v thc hin chn s t pha nh cung cp dch v
cho ngi dng  ngn cc cuc gi v tin nhn vn bn khng mong mun tip cn ngi dng
thng qua bt k phng tin no, v d nh im cui VOIP hoc in thoi chuyn cuc gi.</p>

<p>
   bit thm thng tin, hy xem <code>android.provider.BlockedNumberContract</code>
  trong ti liu <a href="{@docRoot}preview/setup-sdk.html#docs-dl">Tham kho
 API</a> c th ti xung.
</p>

<h2 id="call_screening">Sng lc cuc gi</h2>

<p>
  Android N cho php ng dng gi in mc nh sng lc cc cuc gi n. ng dng
  gi in thc hin iu ny bng cch thc thi <code>CallScreeningService</code> mi,
  cho php ng dng gi in thc hin mt s hnh ng da trn
   {@link android.telecom.Call.Details Call.Details} ca cuc gi n nh:
</p>

<ul>
  <li> T chi cuc gi n
  <li> Khng cho php cuc gi lu trong nht k cuc gi
  <li> Khng hin th thng bo v cuc gi cho ngi dng
</ul>

<p>
   bit thm thng tin, hy xem <code>android.telecom.CallScreeningService</code>
  trong ti liu <a href="{@docRoot}preview/setup-sdk.html#docs-dl">Tham kho
 API</a> c th ti xung.
</p>


<h2 id="multi-locale_languages">H tr a bn a, thm nhiu ngn ng</h2>


<p>Android N cho php ngi dng chn <strong>a bn a</strong> trong Settings,
 h tr tt hn cho cc trng hp song ng. Cc ng dng c th s dng
mt API mi  truy xut cc bn a c chn ca ngi dng v sau  mang n
tri nghim ngi dng tinh t hn cho ngi dng a bn a &mdash; nh hin th cc kt qu tm kim bng
nhiu ngn ng v khng yu cu dch cc trang web sang ngn ng m
ngi dng  bit.</p>

<p>Ngoi h tr a bn a, Android N cng m rng danh sch cc ngn ng
kh dng i vi ngi dng. Nn tng ny cung cp hn 25 bin th cho cc ngn ng
c s dng ph bin nh Ting Anh, Ty Ban Nha, Php v -rp. N cng b sung h tr
mt phn cho hn 100 ngn ng mi.</p>

<p>Cc ng dng c th truy xut danh sch b bn a theo ngi dng bng cch gi <code>LocaleList.GetDefault()</code>.  h tr s lng bn a m rng, Android N ang thay i cch thc
phn gii ti nguyn. Hy m bo bn kim tra v xc minh rng ng dng ca mnh
ang hot ng nh mong mun theo l-gic phn gii ti nguyn mi ny.</p>

<p> tm hiu v hnh vi phn gii ti nguyn mi v cc thc hnh tt nht bn nn
thc hin theo, hy xem mc <a href="{@docRoot}preview/features/multilingual-support.html">H tr a ngn ng</a>.</p>

<h2 id="icu4">API ICU4J trong Android</h2>

<p>
  Android N  cung cp mt tp nh cc API <a href="http://site.icu-project.org/">ICU4J</a> trong khun kh Android thuc
  gi <code>android.icu</code>. Vic chuyn nhp sang rt d dng v hu ht ch lin quan n
  vic i t khng gian tn <code>com.java.icu</code> thnh
  <code>android.icu</code>. Nu bn ang s dng gi ICU4J trong ng dng
  ca mnh th vic chuyn i sang cc API <code>android.icu</code> c cung cp trong khun kh
   Android c th gip lm gim ng k kch thc ca tp APK.
</p>

<p>
   tm hiu thm v API ICU4J trn Android, hy xem <a href="{@docRoot}preview/features/icu4j-framework.html">H tr ICU4J</a>.
</p>


<h2 id="gles_32">API OpenGL&trade; ES 3.2</h2>

<p>Android N b sung cc giao din khun kh v h tr nn tng cho OpenGL ES 3.2, bao gm:</p>

<ul>
  <li> Mi phn m rng trong <a class="external-link" href="https://www.khronos.org/registry/gles/extensions/ANDROID/ANDROID_extension_pack_es31a.txt">Gi Tin ch m rng Android</a></a> (AEP) ngoi tr <code>EXT_texture_sRGB_decode</code>
  <li> B m khung hnh du chm ng cho HDR v to bng tr hon.
  <li> Cc lnh v BaseVertex cho php chia gi v truyn pht hiu qu hn.
  <li> Kim sot truy cp b m mnh m  gim ph tn qun l ca WebGL.
</ul>

<p>API khun kh cho OpenGL ES 3.2 trn Android N c cung cp vi lp
<code>GLES32</code>. Khi s dng OpenGL ES 3.2, hy m bo khai bo
yu cu trong tp bn k khai ca bn bng th <code>&lt;uses-feature&gt;</code> v
thuc tnh <code>android:glEsVersion</code>. </p>

<p> bit thng tin v s dng OpenGL ES, bao gm cch kim tra phin bn
 OpenGL ES c h tr ca thit b ti thi gian chy, hy xem mc <a href="{@docRoot}guide/topics/graphics/opengl.html">Hng dn API OpenGL ES</a>.</p>


<h2 id="android_tv_recording">Ghi li trn Android TV</h2>

<p>Android N b sung kh nng ghi v pht li ni dung t cc dch v
ngun vo ca Android TV thng qua cc API ghi li. c xy dng da trn cc API
chuyn dch thi gian sn c, cc dch v ngun vo TV c th kim sot d liu ca knh no c php ghi li, cch thc
lu tr cc phin c ghi li cng nh qun l tng tc ca ngi dng vi ni dung ghi li. </p>

<p> bit thm thng tin, hy xem <a href="{@docRoot}preview/features/tv-recording-api.html">API ghi li ca Android TV</a>.</p>


<h2 id="android_for_work">Android cho Cng vic</h2>

<p>Android cho Cng vic b sung nhiu tnh nng mi v cc API cho thit b chy Android N.
Di y l mt s im ni bt &mdash;  xem danh sch y  cc cp nht ca Android N
lin quan n Android cho Cng vic, vui lng xem Cc thay i ca Android cho Cng vic.</p>

<h3 id="work_profile_security_challenge">Th thch bo mt cu hnh cng vic </h3>

<p>
  Ngi s hu cu hnh c th ch nh mt th thch bo mt ring cho cc ng dng ang chy trong
  cu hnh cng vic. Th thch cng vic c hin th khi ngi dng c gng m
  bt k ng dng cng vic no. Hon tt thnh cng th thch bo mt s m kha
  cu hnh cng vic v gii m n nu cn. i vi ngi s hu cu hnh,
  <code>ACTION_SET_NEW_PASSWORD</code> s yu cu ngi dng t mt th thch
  cng vic v <code>ACTION_SET_NEW_PARENT_PROFILE_PASSWORD</code> s yu cu
  ngi dng t kha thit b.
</p>

<p>
  Ngi s hu cu hnh c th t cc chnh sch mt khu ring bit cho th thch cng vic
  (nh  di m PIN cn thit hoc c th s dng du vn tay
    m kha cu hnh hay khng) bng <code>setPasswordQuality()</code>,
 <code>setPasswordMinimumLength()</code> v cc phng thc lin quan. Ngi s hu
  cu hnh cng c th ci kha thit b bng thc th <code>DevicePolicyManager</code>
 c tr v bi phng thc <code>getParentProfileInstance()</code> mi.
  Ngoi ra, ngi s hu cu hnh c th ty chnh mn hnh xc thc thng tin cho
  th thch cng vic bng cc phng thc <code>setOrganizationColor()</code> v
   <code>setOrganizationName()</code> mi.
</p>
<h3 id="turn_off_work">Tt cng vic </h3>

<p>Trn mt thit b c cu hnh cng vic, ngi dng c th bt hoc tt ch  cng vic. Khi ch  cng vic c
tt ngi dng c qun l s tm thi b tt, khin v hiu ha cc ng dng
cu hnh cng vic, ng b chy ngm v cc thng bo. iu ny bao gm c ng dng
ca ngi s hu cu hnh. Khi ch  cng vic b tt, h thng s hin th biu tng
trng thi lin tc  nhc ngi dng  rng h khng th khi chy cc ng dng cng vic. Trnh khi chy
s ch bo rng cc ng dng v widget cng vic khng kh dng. </p>

<h3 id="always_on_vpn">VPN lun bt </h3>

<p>Ngi s hu thit b v ngi s hu cu hnh c th m bo rng nhng ng dng cng vic lun kt ni
thng qua mt VPN ch nh. H thng s t ng khi ng VPN  sau khi
thit b khi ng.</p>

<p>
  Cc phng thc <code>DevicePolicyManager</code> mi gm
  <code>setAlwaysOnVpnPackage()</code> v
  <code>getAlwaysOnVpnPackage()</code>.
</p>

<p>Do cc dch v VPN c th c gn kt trc tip bi h thng m khng cn tng tc
ca ng dng, cc my khch VPN cn x l cc im bt u cho VPN lun bt. Ging
trc y, cc dch v c ch nh ti h thng bng mt b lc  nh ph hp vi
hnh ng <code>android.net.VpnService</code>. </p>

<p>
  Ngi dng cng c th t th cng cc my khch VPN lun bt c ci t cc phng thc
   <code>VPNService</code> trong ngi dng chnh bng
  <strong>Settings&gt;More&gt;Vpn</strong>.
</p>

<h2 id="accessibility_enhancements">Ci tin tr nng</h2>

<p>Android N nay  h tr Ci t Kh nng nhn trc tip trn mn hnh Cho mng khi thit lp
thit b mi. iu ny gip ngi dng rt d dng khm ph v cu hnh
cc tnh nng tr nng trn thit b ca h, bao gm c ch phng i, c
phng ch, kch thc hin th v TalkBack. </p>

<p>Vi cc tnh nng tr nng c b tr ngy cng d thy hn, khi c bt
kh nng ngi dng s th ng dng ca bn s cao hn. Hy m bo bn kim th ng dng ca mnh
trc vi cc ci t ny c bt. Bn c th bt chng trong Settings &gt;
Accessibility.</p>

<p>Ngoi ra, trong Android N, cc dch v tr nng  c th tr gip ngi dng b cc tn thng
vn ng chm vo mn hnh. API mi cho php xy dng cc dch v vi nhng
tnh nng nh theo di chuyn ng ca khun mt, theo di chuyn ng ca mt, qut im, v.v. nhm
p ng nhu cu nhng ngi dng ny.</p>

<p> bit thm thng tin, hy xem <code>android.accessibilityservice.GestureDescription</code>
	  trong ti liu <a href="{@docRoot}preview/setup-sdk.html#docs-dl">Tham kho API</a> c th ti xung.</p>


<h2 id="direct_boot">Khi ng Trc tip</h2>

<p>Khi ng Trc tip ci thin thi gian khi ng ca thit b v cho php cc ng dng
 ng k c chc nng hn ch ngay c sau khi khi ng li ngoi d kin.
V d, nu mt thit b c m ha khi ng li khi ngi dng ang ng th
bo thc, tin nhn v cc cuc gi n  ng k c th tip tc thng bo
cho ngi dng nh thng l. iu ny cng c ngha l cc dch v tr nng cng s
   kh dng ngay sau khi khi ng xong.</p>

<p>Khi ng Trc tip s dng m ha theo tp trong Android N
 bt cc chnh sch m ha chi tit cho c d liu ca h thng v ng dng.
H thng s s dng mt b lu tr m ha thit b cho d liu h thng c chn v d liu ng dng
 ng k cng khai. Theo mc nh, mt b lu tr m ha thng tin xc thc s c s dng cho mi
   d liu h thng, d liu ngi dng, ng dng v d liu ca ng dng khc. </p>

<p>Trong qu trnh khi ng, h thng s khi ng vo ch  hn ch v ch c quyn truy cp ti
d liu m ha thit b m thi, v khng c quyn truy cp thng thng ti ng dng hoc d liu.
Nu bn c cc thnh phn mun chy trong ch  ny th bn c th ng k
chng bng cch t c trong bn k khai. Sau khi khi ng, h thng s kch hot
cc thnh phn  ng k bng cch truyn pht  nh <code>LOCKED_BOOT_COMPLETED</code>
. H thng s m bo cho d liu m ha thit b  ng k s kh dng
trc khi m kha. Mi d liu khc s khng kh dng cho ti khi Ngi dng xc nhn thng tin xc thc trn mn hnh kha
   ca h  gii m n. </p>

 bit thm thng tin, hy xem <a href="{@docRoot}preview/features/direct-boot.html">Khi ng Trc tip</a>.</p>
</p>


<h2 id="key_attestation">Chng thc kha</h2>

<p>Cc b lu tr kha da trn phn cng cung cp mt phng thc an ton hn rt nhiu  to, lu tr,
v s dng cc kha mt m trn thit b Android. Chng bo v cc kha trc
nhn Linux, trc cc l hng bo mt tim tng ca Android v trc vic trch xut
t cc my b ginh quyn iu khin v b can thip vo cc tp h thng (my b root).</p>

<p>Android N  a ra tnh nng Chng thc kha  s dng cc b lu tr kha da trn phn cng mt cch
 d dng v bo mt hn. Cc ng dng v dch v khng thuc thit b c th s dng Chng thc
kha  xc nh chc chn xem mt cp kha RSA hoc EC c
da trn phn cng hay khng, cc c im ca cp kha  l g v
  cc rng buc no c p dng cho vic s dng v tnh hp l ca cp kha . </p>

<p>Cc ng dng v dch v khng thuc thit b c th yu cu thng tin v mt cp kha
thng qua chng ch chng thc X.509. Chng ch ny phi c k bi mt kha
chng thc hp l. Kha chng thc l mt kha k ECDSA, c
a vo b lu tr kha da trn phn cng ca thit b ti nh my.
Do , mt chng ch chng thc c k bi kha
chng thc hp l s xc nhn s tn ti ca b lu tr kha da trn phn cng, km theo
   chi tit v cc cp kha trong b lu tr kha .</p>

<p> chc chn thit b ang s dng nh
Android bo mt, chnh thc t nh my, Chng thc kha yu cu <a class="external-link" href="https://source.android.com/security/verifiedboot/verified-boot.html#bootloader_requirements">bootloader</a>
 ca thit b cung cp thng tin sau cho <a class="external-link" href="https://source.android.com/security/trusty/index.html">Mi trng Thc thi
  An ton (TEE)</a>:</p>

<ul>
<li>Phin bn HH v cp v li c ci t trn thit b</li>
<li>Kha cng khai <a href="https://source.android.com/security/verifiedboot/index.html" class="external-link">Khi ng c xc thc</a> v trng thi kha</li>
  </ul>

<p> bit thm thng tin v tnh nng b lu tr kha da trn phn cng,
hy xem hng dn <a href="https://source.android.com/security/keystore/" class="external-link">B lu tr kha da trn phn cng</a>.</p>

<p>Ngoi Chng thc kha, Android N cng gii thiu
   cc kha da vo vn tay m khng c thu hi khi ng k vn tay.</p>

<h2 id="network_security_config">Cu hnh Bo mt mng</h2>

<p>Trong Android N, cc ng dng c th ty bin hnh vi ca cc kt ni
bo mt (HTTPS, TLS) ca chng mt cch an ton m khng cn chnh sa m nh s dng khai bo
<em>Cu hnh Bo mt mng</em> thay v s dng cc API lp trnh truyn thng
d xy ra li (vd: X509TrustManager).</p>

  <p>Cc tnh nng c h tr:</p>
<ul>
<li><b>Ngun tin cy ty chnh.</b> Cho php mt ng dng ty chnh
Nh cung cp chng ch (CA) no s c tin cy cho cc kt ni bo mt ca ng dng. V
d, tin cy cc chng ch t k c th hoc mt b gii hn cc CA cng khai.
</li>
<li><b>Ch khng ch khi g li.</b> Cho php nh pht trin ng dng an ton g li
cc kt ni bo mt ca ng dng m khng to thm ri ro cho phn c s
 ci t.
</li>
<li><b>Khng s dng truyn gi vn bn cha m ha.</b> Cho php mt ng dng t bo v mnh khi vic
v tnh s dng truyn gi vn bn cha m ha cleartext.</li>
<li><b>Ghim chng ch.</b> Mt tnh nng nng cao cho php mt ng dng
  gii hn cc kha my ch no l an ton i vi cc kt ni bo mt.</li>
</ul>

<p> bit thm thng tin, hy xem <a href="{@docRoot}preview/features/security-config.html">Cu hnh Bo mt
 mng</a>.</p>

<h2 id="default_trusted_ca">Nh cung cp Chng ch An ton mc nh</h2>

<p>Theo mc nh, cc ng dng nhm mc tiu Android N ch tin cy cc chng ch do h thng cp
v khng cn tin cy cc Nh cung cp chng ch (CA) do ngi dng thm vo. Cc ng dng nhm mc tiu Android
N mun tin cy cc CA do ngi dng thm vo nn s dng
<a href="{@docRoot}preview/features/security-config.html">Cu hnh Bo mt mng</a>
ch nh cch thc tin cy cc CA ca ngi dng.</p>

<h2 id="apk_signature_v2">Lc  ch k s v2 cho tp APK</h2>

<p>Lp PackageManager nay  h tr xc thc ng dng bng Lc  ch k s v2
APK. Lc  ch k s v2 APK l mt lc  ch k s trn ton b tp
lm tng ng k tc  xc thc v tng cng s bo m
   ton vn bng cch pht hin cc thay i tri php i vi cc tp APK.</p>

<p> bo m tng thch ngc, mt tp APK phi c k bng lc
ch k s v1 (Lc  ch k s JAR) trc khi c k bng lc  ch k s v2.
Vi lc  ch k s v2, qu trnh xc thc s tht bi nu bn k tp APK bng mt
  chng ch khc sau khi k bng lc  v2. </p>

<p>H tr cho lc  ch k s v2 cho tp AKP s c sau trong N Developer
Preview.</p>

<h2 id="scoped_directory_access">Truy cp th mc theo phm vi</h2>

<p>Trong Android N, ng dng c th s dng cc API mi  yu cu truy cp vo cc th mc <a href="{@docRoot}guide/topics/data/data-storage.html#filesExternal">b nh lu tr
ngoi</a> ring, bao gm cc th mc trn phng tin c th tho ra nh th
SD. Cc API mi  ti gin cch thc ng dng ca bn truy cp cc th mc lu tr ngoi
tiu chun nh th mc <code>Pictures</code>. Cc ng dng
nh ng dng qun l nh c th s dng cc API ny thay v s dng
<code>READ_EXTERNAL_STORAGE</code>  cp quyn truy cp ti mi th mc
lu tr, hoc Khun kh Truy cp Lu tr  gip ngi dng di chuyn ti
th mc .</p>

<p>Ngoi ra, cc API mi ny cng n gin ha cc bc m ngi dng thc hin  cp quyn truy cp
b nh lu tr ngoi cho ng dng ca bn. Khi bn s dng cc API mi, h thng s s dng mt UI cp quyn
n gin cung cp cc thng tin chi tit r rng v th mc no ng dng ang
yu cu quyn truy cp.</p>

<p> bit thm thng tin, hy xem ti liu cho nh pht trin
<a href="{@docRoot}preview/features/scoped-folder-access.html">Truy cp
Th mc theo Phm vi</a>.</p>