安卓定位交换机流程分析
一位同事发现当前汽车location的位置位于刷机(在线刷之后)，每次的location初始值(在settings中看到的)不一致。 因为以前一点也没有涉及过这个，所以今天拿出去研究收集博客。
位置的三种工作模式？
从settings-location界面来看，location主要有三种工作模式：
high _ accuracy battery _ saving sensors _ only
对应于代码：
//packages/apps/settings/src/com/Android/settings/location/location mode.javaintmode=settings.secure . }elseif(Emiter==mbatterysaving ) mode=settings.secure.location _ mode _ battery _ saving； }elseif(Emiter==msensorsonly ) mode=settings.secure.location _ mode _ sensors _ only； } setlocationmode (模式； 快速找到setLocationMode
//packages/apps/settings/src/com/Android/settings/location/locationsettingsbase.javapublicvoidsetlocationmase locationtogglingdisabledbyuserrestriction.readthecurrentlocationmodeto/modeto updatethelocationmasterswitch.if (log.info () log.I ) tag，' Restricted user，not setting location mode ' )； } mode=settings.secure.getint (get content resolver (，Settings.Secure.LOCATION_MODE，settings.secure.location ) } return； } intent intent=new intent (mode _ changing _ action )； intent.put extra (current _ mode _ key，mCurrentMode )； intent.putextra(new_mode_key，mode； getActivity ().sendbroadcast(intent，Android.manifest.permission.write _ secure _ settings )； settings.secure.putint (get content resolver (，Settings.Secure.LOCATION_MODE，mode ) )； refreshLocationMode (； 你看起来像在操作Settings.Secure数据库呢。 直接找到吧：
私有状态缓存模式(contentresolvercr，int mode，int userId ) . switch )缓存缓存黑； case location _ mode _ battery _ saving : network=true； 黑； case location _ mode _ high _ accuracy : GPS=true； 网络=true； 黑； 默认：图形封装模式(invalidlocationmode : )； //noteit ' simportantthatwesetthenlpmodefirst.thegoogleimplementation//ofnlpclearsitsnlpconsentsettinganytimeitreceiver location manager.providers _ changed _ actionbroadcastandnlpisdisabled.aled/itshowsannlpconsentdialoganytimeitreceiive NLP is//enabled，and the NLP consent is not set. If 1 ) we were to enable GPS first， //2 ) asetupwizardhasitsownlpconsentuithatsetsthenlpconsentsetting， //and 3) thereceiverhappenedtocompletebeforeweenabler thenthegoogle//nlpwoulddetecttheattempttoenablenlpandshowaredundantnttne dialog.thenthepeoplewhowrotethesetupwizardwouldbesad.booleannlpsuccess=settings.setlocationproviderenabledfored settings.secure.setlocationproviderenabledforuserid (Cr，LocationManager.GPS_PROVIDER，GPS，user return GPS success ns ) } publicstaticfinalbooleansetlocationproviderenabledforuser (contentresolvercr，String provider，boolean enabled， intuserid(synchronized ) mlocationsettingslock ) { //to ensure thread safety， wewritetheprovidernamewitha ' ' or '-'//andletthesettingsproviderhandleitratherthanreadingandmodifying//thelistofenablenabled }returnputstringforuser(Cr，settings.secure.location _ providers _ allowed，provider，userId )； }是，字段为： settings.secure.location _ providers _ allowed
让我们看看实际的机器测试：
旧规则，一条命令就可以了
adbshellsettingsgetsecurelocation _ providers _ allowed
关闭位置：
结果为空
打开位置，high_accuracy模式
网络、gps
打开位置，电池_保存模式
网络
打开location，sensors_only模式
gps
这样.也学到了科普的东西！