Android后台开启服务默默拍照

最近项目原因，需要编写一后台运行的程序，在给定时间间隔下进行拍照，关键技术主要是：1、开启服务；2、在不不预览的情况下，进行拍照操作。3、使用AlarmManager进行定时操作。

资源清单如下：

<manifest xmlns:Android="http://schemas.android.com/apk/res/android"
    package="com.yang.testservice"
    android:versionCode="1"
    android:versionName="1.0" >

<uses-feature android:name="android.hardware.camera" />
    <uses-feature android:name="android.hardware.camera.autofocus" />

<uses-permission android:name="android.permission.CAMERA" />
    <uses-permission android:name="android.permission.FLASHLIGHT" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

<uses-feature android:name="android.hardware.camera.any" />

<uses-sdk
        android:minSdkVersion="13"
        android:targetSdkVersion="15" />

<application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/title_activity_main" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

<service android:name="com.yang.service.LocalService" />
    </application>

</manifest>

服务代码如下：

package com.yang.service;

import java.io.IOException;

import android.app.AlarmManager;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.hardware.Camera;
import android.os.Binder;
import android.os.IBinder;
import android.util.Log;
import android.view.SurfaceView;
import android.widget.Toast;

import com.yang.handle.PhotoHandler;
import com.yang.testservice.MainActivity;
import com.yang.testservice.R;

public class LocalService extends Service {

private AlarmManager am = null;
 private Camera camera;

private final IBinder mBinder = new LocalBinder();

private NotificationManager mNM;

private int NOTIFICATION = R.string.local_service_started;

/**
  * Class for clients to access. Because we know this service always runs in
  * the same process as its clients, we don't need to deal with IPC.
  */
 public class LocalBinder extends Binder {
  public LocalService getService() {
   return LocalService.this;
  }

}

@Override
 public void onCreate() {
  mNM = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
  showNotification();
  init();
 }

private void init() {
  am = (AlarmManager) getSystemService(ALARM_SERVICE);

camera = openFacingBackCamera();

// 注册广播
  IntentFilter filter = new IntentFilter();
  filter.addAction("com.vegetables_source.alarm");
  registerReceiver(alarmReceiver, filter);

Intent intent = new Intent();
  intent.setAction("com.vegetables_source.alarm");
  PendingIntent pi = PendingIntent.getBroadcast(this, 0, intent, 0);

am.setRepeating(AlarmManager.RTC_WAKEUP, System.currentTimeMillis(),
    1000 * 10, pi);// 马上开始，每1分钟触发一次
 }

@Override
 public int onStartCommand(Intent intent, int flags, int startId) {
  Log.i("LocalService", "Received start id " + startId + ": " + intent);

return START_STICKY;
 }

@Override
 public void onDestroy() {
  mNM.cancel(NOTIFICATION);

cancelAlertManager();

if (camera != null) {
   camera.release();
   camera = null;
  }

Toast.makeText(this, R.string.local_service_stopped, Toast.LENGTH_SHORT)
    .show();
 }

@Override
 public IBinder onBind(Intent intent) {
  return mBinder;
 }

/**
  * Show a notification while this service is running.
  */
 private void showNotification() {
  CharSequence text = getText(R.string.local_service_started);

Notification notification = new Notification(R.drawable.stat_running,
    text, System.currentTimeMillis());

PendingIntent contentIntent = PendingIntent.getActivity(this, 0,
    new Intent(this, MainActivity.class), 0);

notification.setLatestEventInfo(this,
    getText(R.string.local_service_label), text, contentIntent);

mNM.notify(NOTIFICATION, notification);
 }