1 page.title=Khi ng Trc tip 2 page.keywords=preview,sdk,direct boot 3 page.tags=androidn 4 page.image=images/cards/card-nyc_2x.jpg 5 6 @jd:body 7 8 <div id="tb-wrapper"> 9 <div id="tb"> 10 <h2>Trong ti liu ny</h2> 11 <ol> 12 <li><a href="#run">Yu cu Truy cp Chy trong qu trnh Khi ng Trc tip</a></li> 13 <li><a href="#access">Truy cp B nh Lu tr M ha ca Thit b</a></li> 14 <li><a href="#notification">Nhn thng bo M kha ca Ngi dng</a></li> 15 <li><a href="#migrating">Chuyn nhp D liu C sn</a></li> 16 <li><a href="#testing">Kim th ng dng Nhn bit M ha ca bn</a></li> 17 </ol> 18 </div> 19 </div> 20 21 <p>Android N chy trong ch <i>Khi ng Trc tip</i> an ton 22 khi thit b c bt ngun nhng ngi dng cha m kha 23 thit b. h tr ch ny, h thng cung cp hai v tr lu tr d liu:</p> 24 25 <ul> 26 <li><i>Lu tr m ha thng tin xc thc</i>, l v tr lu tr mc nh 27 v ch kh dng sau khi ngi dng m kha thit b.</li> 28 <li><i>Lu tr m ha thit b</i>, l v tr lu tr kh dng cho c 29 ch Khi ng Trc tip v sau khi ngi dng m kha thit b.</li> 30 </ul> 31 32 <p>Theo mc nh, cc ng dng khng chy trong qu trnh ch Khi ng Trc tip. 33 Nu ng dng ca bn cn thc hin hnh ng trong ch Khi ng Trc tip th bn c th ng k 34 cc thnh phn ng dng cn chy trong ch ny. Mt s trng hp s dng ph bin 35 cho cc ng dng cn chy trong ch Khi ng Trc tip gm:</p> 36 37 <ul> 38 <li>ng dng c thng bo theo lch, nh ng dng 39 ng h bo thc.</li> 40 <li>ng dng cung cp cc thng bo quan trng cho ngi dng nh ng dng SMS.</li> 41 <li>ng dng cung cp cc dch v tr nng nh Talkback.</li> 42 </ul> 43 44 <p>Nu ng dng ca bn cn truy cp d liu khi ang chy trong ch Khi ng Trc tip th hy s dng 45 lu tr m ha thit b. B nh lu tr c m ha ca thit b c cha d liu 46 c m ha bng mt kha ch kh dng sau khi thit b thc hin mt 47 ln khi ng c xc thc thnh cng.</p> 48 49 <p>i vi d liu cn c m ha bng mt kha lin kt ti thng tin xc thc 50 ca ngi dng nh m PIN hoc mt khu th hy s dng b nh lu tr m ha thng tin xc thc. 51 B nh lu tr m ha thng tin xc thc ch kh dng sau khi ngi dng m kha 52 thnh cng thit b, tnh n khi ngi dng khi ng li thit b mt ln na. Nu 53 ngi dng m mn hnh kha sau khi m kha thit b th thao tc ny khng kha 54 b nh m ha thng tin xc thc.</p> 55 56 <h2 id="run">Yu cu Truy cp Chy trong qu trnh Khi ng Trc tip</h2> 57 58 <p>Cc ng dng phi ng k cc thnh phn ca chng vi h thng trc khi chng 59 c th chy trong ch Khi ng Trc tip hoc truy cp b nh lu tr 60 m ha thit b. ng dng ng k vi h thng bng cch nh du cc thnh phn l 61 <i>nhn bit m ha</i>. nh du cc thnh phn ca bn l nhn bit m ha, hy t thuc tnh 62 <code>android:encryptionAware</code> thnh true trong bn k khai.<p> 63 64 <p>Cc thnh phn nhn bit m ha c th ng k nhn mt thng ip truyn pht 65 <code>LOCKED_BOOT_COMPLETED</code> t 66 h thng khi thit b c khi ng li. Lc ny, b nh lu tr 67 m ha thit b s kh dng v thnh phn ca bn c th thc thi cc tc v cn c 68 chy trong ch Khi ng Trc tip, nh kch hot bo thc t.</p> 69 70 <p>on m sau l mt v d v cch ng k mt 71 {@link android.content.BroadcastReceiver} l nhn bit m ha v thm mt 72 b lc nh cho <code>LOCKED_BOOT_COMPLETED</code> trong bn k khai ca ng dng:</p> 73 74 <pre> 75 <receiever 76 android:encryptionAware="true" > 77 ... 78 <intent-filter> 79 <action android:name="android.intent.action.LOCKED_BOOT_COMPLETED" /> 80 </intent-filter> 81 </receiver> 82 </pre> 83 84 <p>Khi ngi dng m kha thit b th mi thnh phn c th truy cp 85 c b nh lu tr m ha thit b ln b nh lu tr m ha thng tin xc thc.</p> 86 87 <h2 id="access">Truy cp B nh Lu tr M ha ca Thit b</h2> 88 89 <p> truy cp b nh lu tr m ha thit b, hy to mt thc th 90 {@link android.content.Context} th hai bng cch gi 91 <code>Context.createDeviceEncryptedStorageContext()</code>. Tt c cc lnh gi 92 API b nh lu tr u s dng bi cnh ny truy cp b nh lu tr m ha thit b. 93 V d sau s truy cp b nh lu tr m ha ca thit b v m mt tp 94 d liu ng dng c sn:</p> 95 96 <pre> 97 Context directBootContext = Context.createDeviceEncryptedStorageContext(); 98 // Access appDataFilename that lives in device encrypted storage 99 FileInputStream inStream = directBootContext.openFileInput(appDataFilename); 100 // Use inStream to read content... 101 </pre> 102 103 <p>Ch s dng b nh lu tr m ha ca thit b 104 cho thng tin phi truy cp c trong ch Khi ng Trc tip. 105 Khng s dng b nh lu tr m ha ca thit b lm b lu tr m ha cho mc ch chung. 106 i vi thng tin c nhn ca ngi dng, hoc d liu c m ha khng cn thit 107 trong ch Khi ng Trc tip th hy s dng b nh lu tr m ha thng tin xc thc.</p> 108 109 <h2 id="notification">Nhn thng bo M kha ca Ngi dng</h2> 110 111 <p>Mt khi ngi dng m kha thit b sau khi khi ng li, ng dng ca bn c th chuyn sang 112 truy cp b nh lu tr m ha thng tin xc thc v s dng cc dch v thng thng ca h thng 113 ph thuc vo thng tin xc thc ngi dng.</p> 114 115 <p> nhn thng bo khi ngi dng m kha thit b sau khi khi ng li, 116 hy ng k mt {@link android.content.BroadcastReceiver} t mt thnh phn ang chy 117 lng nghe thng bo <code>ACTION_USER_UNLOCKED</code>. Hoc bn c th 118 nhn thng bo c sn {@link android.content.Intent#ACTION_BOOT_COMPLETED 119 ACTION_BOOT_COMPLETED} lc ny s ch bo thit b khi ng xong v 120 ngi dng m kha thit b.</p> 121 122 <p>Bn c th truy vn trc tip bit ngi dng m kha thit b hay cha bng cch gi 123 <code>UserManager.isUserUnlocked()</code>.</p> 124 125 <h2 id="migrating">Chuyn nhp D liu C sn</h2> 126 127 <p>Nu ngi dng cp nht thit b ca h s dng ch Khi ng Trc tip th bn c th c d liu 128 hin hu cn c chuyn nhp sang b nh lu tr m ha ca thit b. S dng 129 <code>Context.migrateSharedPreferencesFrom()</code> v 130 <code>Context.migrateDatabaseFrom()</code> chuyn nhp d liu v ty chn v c s d liu 131 gia b nh lu tr m ha thng tin xc thc v b nh lu tr m ha thit b.</p> 132 133 <p>Hy phn on hp l nht khi quyt nh d liu no nn chuyn nhp t b nh lu tr m ha 134 thng tin xc thc sang b nh lu tr m ha thit b. Bn khng nn di chuyn 135 thng tin c nhn ca ngi dng nh mt khu hoc cc m thng bo cp quyn sang 136 b nh lu tr m ha thit b. Trong mt s trng hp, bn c th cn qun l 137 cc b d liu ring bit trong hai b lu tr m ha.</p> 138 139 <h2 id="testing">Kim th ng dng Nhn bit M ha ca bn</h2> 140 141 <p>Kim th ng dng nhn bit m ha bng cch s dng ch Khi ng Trc tip mi. C 142 hai cch kch hot Khi ng Trc tip.</p> 143 144 <p class="caution"><strong>Cn trng:</strong> Kch hot Khi ng Trc tip 145 s xa sch mi d liu ngi dng trn thit b.</p> 146 147 <p>Trn cc thit b c h tr c Android N c ci t, kch hot 148 Khi ng Trc tip bng cch thc hin mt trong cc thao tc sau:</p> 149 150 <ul> 151 <li>Trn thit b, bt <b>Developer options</b> nu cha hy bt bng cch 152 vo <b>Settings > About phone</b> v nhn vo <b>Build number</b> 153 by ln. Khi mn hnh ty chn cho nh pht trin kh dng, hy vo 154 <b>Settings > Developer options</b> v chn 155 <b>Convert to file encryption</b>.</li> 156 <li>S dng cc lnh shell adb sau kch hot ch Khi ng Trc tip: 157 <pre class="no-pretty-print"> 158 $ adb reboot-bootloader 159 $ fastboot --wipe-and-use-fbe 160 </pre> 161 </li> 162 </ul> 163 164 <p>Cng c mt ch Khi ng Trc tip gi lp trong trng hp bn cn chuyn i 165 cc ch trn thit b th nghim. Ch nn s dng ch Gi lp trong qu trnh 166 pht trin v c th lm mt d liu. kch hot ch Khi ng Trc tip gi lp, 167 hy t mu hnh kha cho thit b, chn "No thanks" nu c yu cu 168 bt mn hnh khi ng bo mt khi t mt mu hnh kha v sau s dng 169 lnh shell adb sau:</p> 170 171 <pre class="no-pretty-print"> 172 $ adb shell sm set-emulate-fbe true 173 </pre> 174 175 <p>Hy s dng lnh sau tt ch Khi ng Trc tip gi lp:</p> 176 177 <pre class="no-pretty-print"> 178 $ adb shell sm set-emulate-fbe false 179 </pre> 180 181 <p>S dng cc lnh ny c th khin cho thit b khi ng li.</p> 182
