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：

<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" />

</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);
}

private void cancelAlertManager() {
Intent intent = new Intent();
intent.setAction("com.vegetables_source.alarm");
PendingIntent pi = PendingIntent.getBroadcast(this, 0, intent, 0);
am.cancel(pi);

// 注销广播
unregisterReceiver(alarmReceiver);
}

BroadcastReceiver alarmReceiver = new BroadcastReceiver() {

@Override
public void onReceive(Context context, Intent intent) {
if ("com.vegetables_source.alarm".equals(intent.getAction())) {

if (camera != null) {
SurfaceView dummy = new SurfaceView(getBaseContext());
try {
camera.setPreviewDisplay(dummy.getHolder());
} catch (IOException e) {
e.printStackTrace();
}
camera.startPreview();

camera.takePicture(null, null, new PhotoHandler(
getApplicationContext()));
}

}

}
};

private Camera openFacingBackCamera() {
Camera cam = null;
Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
;
for (int camIdx = 0, cameraCount = Camera.getNumberOfCameras(); camIdx < cameraCount; camIdx++) {
Camera.getCameraInfo(camIdx, cameraInfo);
if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_BACK) {
try {
cam = Camera.open(camIdx);
} catch (RuntimeException e) {
e.printStackTrace();
}
}
}

return cam;
}
}

进行拍照存储的操作代码如下：

package com.yang.handle;

import java.io.File;
import java.io.FileOutputStream;
import java.text.SimpleDateFormat;
import java.util.Date;

import android.content.Context;
import android.hardware.Camera;
import android.hardware.Camera.PictureCallback;
import android.os.Environment;
import android.widget.Toast;

public class PhotoHandler implements PictureCallback {

private final Context context;

public PhotoHandler(Context context) {
this.context = context;
}

@Override
public void onPictureTaken(byte[] data, Camera camera) {

File pictureFileDir = getDir();

if (!pictureFileDir.exists() && !pictureFileDir.mkdirs()) {

Toast.makeText(context, "Can't create directory to save image.",
Toast.LENGTH_LONG).show();
return;

}

SimpleDateFormat dateFormat = new SimpleDateFormat("yyyymmddhhmmss");
String date = dateFormat.format(new Date());
String photoFile = "Picture_" + date + ".jpg";

String filename = pictureFileDir.getPath() + File.separator + photoFile;

File pictureFile = new File(filename);
System.out.println("filename is "+ filename);

try {
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(data);
fos.close();
Toast.makeText(context, "New Image saved:" + photoFile,
Toast.LENGTH_LONG).show();
} catch (Exception error) {
Toast.makeText(context, "Image could not be saved.",
Toast.LENGTH_LONG).show();
}
}

private File getDir() {
File sdDir = Environment
.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
return new File(sdDir, "ServiceCamera");
}
}

项目代码如下：

具体下载目录在 /2013年资料/7月/7日/Android后台开启服务默默拍照

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Android后台开启服务默默拍照

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