最近在做行车记录仪的事情，由于车载设备上的锂电池容量比较小，所以在停车熄火，保存数据后需要自动关机，由于Shutdown的权限不对普通应用开放，所以需要在源码下编译代码。可以自己写个BroadcastReceiver放到Setting源码里，也可以是独立应用。 manifest节点需要声明系统级uid： android:sharedUserId="android.uid.system" 以及关机权限： <uses-permission android:name="android.permission.SHUTDOWN"/> 以上这两点在Setting的AndroidManifest里都有，所以就不用我们手动添加了。
然后我在Application里声明了两个全局变量，用来存储当前的电源状态和已经断开电源的秒数： /** * 电源是否连接 */ public static boolean isPowerConnect = true; /** * 电源断开的秒数 */ public static int OffSecond = 0; 接着就是PowerStateChangeReceiver： package com.android.settings; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.os.Handler; import android.os.Message; import android.widget.Toast; public class PowerStateChangeReceiver extends BroadcastReceiver { private Context context; @Override public void onReceive(Context context, Intent intent) { this.context = context; Screenshot.OffSecond = 0; if ("android.intent.action.ACTION_POWER_CONNECTED".equals(intent .getAction())) { Screenshot.isPowerConnect = true; //Toast.makeText(context, "CONNECTED", Toast.LENGTH_SHORT).show(); } else if ("android.intent.action.ACTION_POWER_DISCONNECTED" .equals(intent.getAction())) { Screenshot.isPowerConnect = false; //Toast.makeText(context, "DISCONNECTED", Toast.LENGTH_SHORT).show(); new Thread(new shutdownThread()).start(); } } /** * Shutdown * * @param context */ public void shutdown(Context context) { try { Intent intent = new Intent( "android.intent.action.ACTION_REQUEST_SHUTDOWN"); intent.putExtra("android.intent.extra.KEY_CONFIRM", false); intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); context.startActivity(intent); } catch (Exception e) { } Toast.makeText(context, context.getResources().getString(R.string.shutdown_now), Toast.LENGTH_SHORT).show(); } public class shutdownThread implements Runnable { @Override public void run() { synchronized (shutdownHandler) { while (!Screenshot.isPowerConnect) { try { Thread.sleep(1000); Message message = new Message(); message.what = 1; shutdownHandler.sendMessage(message); } catch (InterruptedException e) { e.printStackTrace(); } } } } } final Handler shutdownHandler = new Handler() { public void handleMessage(Message msg) { switch (msg.what) { case 1: if (!Screenshot.isPowerConnect) { Screenshot.OffSecond++; } else { Screenshot.OffSecond = 0; } if (Screenshot.OffSecond == 10 && !Screenshot.isPowerConnect) { shutdown(context); } break; default: break; } } }; } 另外是在setting的AndroidManifest.xml对reveiver的声明： <receiver android:name=".PowerStateChangeReceiver" > <intent-filter> <action android:name="android.intent.action.ACTION_POWER_CONNECTED" /> <action android:name="android.intent.action.ACTION_POWER_DISCONNECTED" /> intent-filter> receiver> okay，大功告成。