SystemProperties跟Settings.System
1 使用 SystemProperties.get
如果属性名称以“ro.”开头,那么这个属性被视为只读属性。一旦设置,属性值不能改变。
如果属性名称以“persist.”开头,当设置这个属性时,其值也将写入/data/property。
JAVA代码如下:
import android.os.SystemProperties;//设定SystemProperties.set("persist.sys.language", "默认值");//读取
String lang= SystemProperties.get("persist.sys.language");//stringint lang = SystemProperties.getInt("persist.sys.language",10);boolean fastfoodenable = SystemProperties.getBoolean("persist.sys.fastfoodenable", false);//boolean
创建与修改android属性用
Systemproperties.set(name, value);
获取android属性用
Systemproperties.get(name);
需要注意的是android属性的名称是有一定的格式要求的,
前缀必须用system\core\init\property_service.c中定义的前缀
property_service.c的内容如下
property_perms[] = {
{ "net.rmnet0.", AID_RADIO, },
{ "net.gprs.", AID_RADIO, },
{ "net.ppp", AID_RADIO, },
{ "net.qmi", AID_RADIO, },
{ "net.lte", AID_RADIO, },
{ "net.cdma", AID_RADIO, },
{ "ril.", AID_RADIO, },
{ "persist.ril.", AID_RADIO, },
{ "persist.ril.cfu.querytype", AID_APP, },
{ "mux.", AID_RADIO, },
{ "mux.", AID_SYSTEM, },
{ "mtk_telephony_mode_slot1", AID_SYSTEM, },
{ "mtk_telephony_mode_slot2", AID_SYSTEM, },
{ "gsm.", AID_RADIO, },
{ "persist.radio", AID_RADIO, },
{ "net.dns", AID_RADIO, },
{ "sys.usb.config", AID_RADIO, AID_SYSTEM },
{ "net.", AID_SYSTEM, },
{ "net.", AID_DHCP, },
{ "dev.", AID_SYSTEM, },
{ "runtime.", AID_SYSTEM, },
{ "hw.", AID_SYSTEM, },
{ "sys.", AID_SYSTEM, },
{ "sys.powerctl", AID_SHELL, },
{ "service.", AID_SYSTEM, },
{ "wlan.", AID_SYSTEM, },
{ "bluetooth.", AID_BLUETOOTH, },
{ "dhcp.", AID_SYSTEM, },
{ "bwc.mm.", AID_SYSTEM, },
{ "dhcp.", AID_DHCP, },
{ "debug.", AID_SYSTEM, },
{ "debug.", AID_SHELL, },
{ "log.", AID_SHELL, },
{ "service.adb.root", AID_SHELL, },
{ "service.adb.tcp.port", AID_SHELL, },
{ "persist.sys.", AID_SYSTEM, },
{ "persist.service.", AID_SYSTEM, },
{ "persist.security.", AID_SYSTEM, },
{ "persist.service.bdroid.", AID_BLUETOOTH, },
{ "selinux." , AID_SYSTEM, },
{ "gps.", AID_GPS, AID_SYSTEM },
{ "persist.af.", AID_MEDIA, },
进行系统属性设置的程序也必须有 system或root权限
如果我们要添加一个property:例如:zhang
路径:
system/core/rootdir/init.rc
它的内容如下
on post-fs-data
# We chown/chmod /data again so because mount is run as root + defaults
chown system system /data
chmod 0771 /data
# We restorecon /data in case the userdata partition has been reset.
restorecon /data # Avoid predictable entropy pool. Carry over entropy from previous boot.
copy /data/system/entropy.dat /dev/urandom # Create dump dir and collect dumps.
# Do this before we mount cache so eventually we can use cache for
# storing dumps on platforms which do not have a dedicated dump partition.
mkdir /data/dontpanic 0750 root log # Collect apanic data, free resources and re-arm trigger
copy /proc/apanic_console /data/dontpanic/apanic_console
chown root log /data/dontpanic/apanic_console
chmod 0640 /data/dontpanic/apanic_console copy /proc/apanic_threads /data/dontpanic/apanic_threads
chown root log /data/dontpanic/apanic_threads
chmod 0640 /data/dontpanic/apanic_threads write /proc/apanic_console 1
# If there is no fs-post-data action in the init.<device>.rc file, you
# must uncomment this line, otherwise encrypted filesystems
# won't work.
# Set indication (checked by vold) that we have finished this action
#setprop vold.post_fs_data_done 1
在on post-fs-data 目录下
setprop persist.sys.zhang 1//persist.sys 前缀名; 1为初始值
PS:不同前缀名权限不同,这里就不一一说明;还有为什么要加载on post-fs-data目录下,这和int.rc的语法有关
2 使用 Settings.System.putInt
这种方式会保存变量到Settings 数据库中,飞行模式等的开关就是用这种方式实现的。
首先需要定义一个系统属性值
路径
frameworks/base/core/java/android/provider/Settings.java
添加一个属性标签
public static final String QS_DYNAMIC_WIFI = "qs_dyanmic_wifi"; /**
* Quick Settings Quick Pulldown
*
* @hide
*/
public static final String QS_QUICK_PULLDOWN = "qs_quick_pulldown"; /**
* Quick Settings Collapse Pane
*
* @hide
*/
public static final String QS_COLLAPSE_PANEL = "qs_collapse_panel"; /**
* Quick Settings Quick access ribbon
*
* @hide
*/
public static final String QS_QUICK_ACCESS = "qs_quick_access";//别忘了在这里面提添加
public static final String[] SETTINGS_TO_BACKUP = {
QS_QUICK_PULLDOWN
STAY_ON_WHILE_PLUGGED_IN, // moved to global
WIFI_USE_STATIC_IP,
WIFI_STATIC_IP,
WIFI_STATIC_GATEWAY,
WIFI_STATIC_NETMASK,
WIFI_STATIC_DNS1,
WIFI_STATIC_DNS2,
BLUETOOTH_DISCOVERABILITY,
BLUETOOTH_DISCOVERABILITY_TIMEOUT,
DIM_SCREEN,
SCREEN_OFF_TIMEOUT,
SCREEN_BRIGHTNESS,
SCREEN_BRIGHTNESS_MODE,
SCREEN_AUTO_BRIGHTNESS_ADJ,
VIBRATE_INPUT_DEVICES,
MODE_RINGER_STREAMS_AFFECTED,
VOLUME_VOICE,
VOLUME_SYSTEM,
VOLUME_RING,
VOLUME_MUSIC,
VOLUME_ALARM,
}
1)获取方法如下:
Settings.System.getInt(getContentResolver(), Settings.System.QS_QUICK_PULLDOWN,0);
第三个参数是默认值
2)设置
Settings.System.putInt(getContentResolver(),Settings.System.QS_QUICK_PULLDOWN, 1);
代码中使用的时候,需要导入包
需要import android.provider.Settings;