adb shell dumpsys的使用

该命令用于打印出当前系统信息，默认打印出设备中所有service的信息，可以在命令后面加指定的service name.
有两种方法可以查看service list:
1. adb shell dumpsys
输出信息的开始部分就是所有运行的service，如下：
Currently running services:
SurfaceFlinger:

accessibility:

account:

activity:

alarm:

appwidget:

audio:

backup:

battery:

batteryinfo:

clipboard:

connectivity:

content:

cpuinfo:

device_policy:

devicestoragemonitor:

diskstats:

dropbox:

entropy:

hardware:

input_method:

iphonesubinfo:

isms:

location:

media.audio_flinger:

media.audio_policy:

media.camera:

media.player:

meminfo:

mount:

netstat:

network_management:

notification:

package:

permission:

phone:

power:

search:

sensorservice:

simphonebook:

statusbar:

telephony.registry:

throttle:

uimode:

usagestats:

 vibrator:

wallpaper:

wifi:

window:
2. adb shell service list
输出结果如下：
Found 49 services:

0       phone: [com.android.internal.telephony.ITelephony]

1       iphonesubinfo: [com.android.internal.telephony.IPhoneSubInfo]

2       simphonebook: [com.android.internal.telephony.IIccPhoneBook]

3       isms: [com.android.internal.telephony.ISms]

4       diskstats: []

5       appwidget: [com.android.internal.appwidget.IAppWidgetService]

6       backup: [android.app.backup.IBackupManager]

7       uimode: [android.app.IUiModeManager]

8       audio: [android.media.IAudioService]

9       wallpaper: [android.app.IWallpaperManager]

10      dropbox: [com.android.internal.os.IDropBoxManagerService]

11      search: [android.app.ISearchManager]

12      location: [android.location.ILocationManager]

13      devicestoragemonitor: []

14      notification: [android.app.INotificationManager]

15      mount: [IMountService]

16      accessibility: [android.view.accessibility.IAccessibilityManager]

17      throttle: [android.net.IThrottleManager]

18      connectivity: [android.net.IConnectivityManager]

19      wifi: [android.net.wifi.IWifiManager]

20      network_management: [android.os.INetworkManagementService]

21      netstat: [android.os.INetStatService]

22      input_method: [com.android.internal.view.IInputMethodManager]

23      clipboard: [android.text.IClipboard]

24      statusbar: [com.android.internal.statusbar.IStatusBarService]

25      device_policy: [android.app.admin.IDevicePolicyManager]

26      window: [android.view.IWindowManager]

27      alarm: [android.app.IAlarmManager]

28      vibrator: [android.os.IVibratorService]

29      hardware: [android.os.IHardwareService]

30      battery: []

31      content: [android.content.IContentService]

32      account: [android.accounts.IAccountManager]

33      permission: [android.os.IPermissionController]

34      cpuinfo: []

35      meminfo: []

36      activity: [android.app.IActivityManager]

37      package: [android.content.pm.IPackageManager]

38      telephony.registry: [com.android.internal.telephony.ITelephonyRegistry]

39      usagestats: [com.android.internal.app.IUsageStats]

40      batteryinfo: [com.android.internal.app.IBatteryStats]

41      power: [android.os.IPowerManager]

42      entropy: []

43      sensorservice: [android.gui.SensorServer]

44      SurfaceFlinger: [android.ui.ISurfaceComposer]

45      media.audio_policy: [android.media.IAudioPolicyService]

46      media.camera: [android.hardware.ICameraService]

47      media.player: [android.media.IMediaPlayerService]

48      media.audio_flinger: [android.media.IAudioFlinger]
查询到运行的system service后，就可以在dumpsys后面加上service的名字，查看指定的service信息。
adb shell dumpsys activity
adb shell dumpsys cpuinfo
adb shell dumpsys battery
adb shell dumpsys window（最后部分可以看到分辨率的信息）
有些service能够接收额外的参数，我们可以使用-h查看帮助信息。
adb shell dumpsys package -h
adb shell dumpsys activity -h