鸿蒙传说

/frameworks/base/packages/SystemUI/src/com/android/systemui/statusbar/policy/BatteryControllerImpl.java在Intent.ACTION_BATTERY_CHANGED broadcast处理中调用fireBatteryLevelChanged()方法fireBatteryLevelChanged中会回掉BatteryStateChangeCallbackframeworks/base/packages/SystemUI/src/com/android/systemui/BatteryMeterView.java中实现了BatteryStateChangeCallback， 并向BatteryControllerImpl注册了，mBatteryController.addCallback(this); public void onAttachedToWindow() {

        super.onAttachedToWindow();

        mBatteryController = Dependency.get(BatteryController.class);

        mBatteryController.addCallback(this);

        mUser = ActivityManager.getCurrentUser();

        getContext().getContentResolver().registerContentObserver(

                Settings.System.getUriFor(SHOW_BATTERY_PERCENT), false, mSettingObserver, mUser);

        updateShowPercent();

        Dependency.get(TunerService.class).addTunable(this, StatusBarIconController.ICON_BLACKLIST);

        Dependency.get(ConfigurationController.class).addCallback(this);

        mUserTracker.startTracking();

    }看下BatteryMeterView中的BatteryStateChangeCallback实现就知道了