Question

我有一个使用GCM从服务器接收消息的IntentService，一切正常，除非我尝试使用android.hardware.Camera拍照，InentService在调用onPictureTaken之前被销毁！，那么在InentService停止之前我应该怎么做才能保存拍摄的照片？

public class GcmIntentService extends IntentService {
   String function;

   public GcmIntentService() {
    super("GcmIntentService");

}
   @Override
    protected void onHandleIntent(Intent intent) {
    Bundle extras = intent.getExtras();
    String msg = intent.getStringExtra("message");
    GoogleCloudMessaging gcm = GoogleCloudMessaging.getInstance(this);
    String messageType = gcm.getMessageType(intent);

    if (!extras.isEmpty()) {
               if (GoogleCloudMessaging.MESSAGE_TYPE_MESSAGE.equals(messageType)) {
               System.out.println("message received");

                   try {
                json = new JSONObject(msg);
                function = json.getString("function");

            } catch (JSONException e) {

                e.printStackTrace();
            }
                    if (function.equals("capture")) {
                System.out
                        .println("capture entereeeeed =====================");

                Capture cap = new Capture(getApplicationContext());
                cap.captureNow();


            }

        }
    }
    GcmBroadcastReceiver.completeWakefulIntent(intent);
}




  @Override
public void onDestroy() {

    if (Capture.camera != null) {
        System.out.println("camera released");
        Capture.camera.release();
    }

    super.onDestroy();
}

}

Capture类，来自vogella教程http://www.vogella.com/tutorials/AndroidCamera/article.html

public class Capture {
Context captureContext = null;
public static Camera camera;
private int cameraId = 0;
final static String DEBUG_TAG = "Capture Class";

public Capture(Context context) {

    captureContext = context;
    // do we have a camera?
    if (!captureContext.getPackageManager().hasSystemFeature(
            PackageManager.FEATURE_CAMERA)) {

        System.out.println("no camera found on this device");
    } else {
        cameraId = findFrontFacingCamera();
        if (cameraId < 0) {

            System.out.println("no front camera found");
        } else {
            camera = Camera.open(cameraId);
        }
    }
}

public void captureNow() {
    System.out.println("capture now entered");
    camera.takePicture(null, null, new PhotoHandler(captureContext));
}

public int findFrontFacingCamera() {
    int cameraId = -1;
    // Search for the front facing camera
    int numberOfCameras = Camera.getNumberOfCameras();
    for (int i = 0; i < numberOfCameras; i++) {
        CameraInfo info = new CameraInfo();
        Camera.getCameraInfo(i, info);
        if (info.facing == CameraInfo.CAMERA_FACING_FRONT) {
            Log.d(DEBUG_TAG, "Camera found");
            cameraId = i;
            break;
        }
    }
    return cameraId;
}

}

PhotoHandler类

public class PhotoHandler implements PictureCallback {
private final Context context;
public static String filename;

public PhotoHandler(Context context) {
    System.out.println("enetered photoHandler");
    this.context = context;

}

@Override
public void onPictureTaken(byte[] data, android.hardware.Camera camera) {
    System.out.println("entered onPicture taken");

    File pictureFileDir = getDir();
    System.out.println("file directory = " + pictureFileDir);

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

        Log.d(Capture.DEBUG_TAG, "Can't create directory to save image.");

        return;

    }

    SimpleDateFormat dateFormat = new SimpleDateFormat("yyyymmddhhmmss");
    String date = dateFormat.format(new Date());
    String photoFile = "Picture_" + date + ".jpg";
    filename = pictureFileDir.getPath() + File.separator + photoFile;

    File pictureFile = new File(filename);


    try {
        FileOutputStream fos = new FileOutputStream(pictureFile);
        fos.write(data);
        fos.close();

        System.out.println("New Image saved: " + photoFile);
        Capture.camera.release();


    } catch (Exception error) {
        Log.d(Capture.DEBUG_TAG,
                "File" + filename + "not saved: " + error.getMessage());

        System.out.println("image could not be saved");
    }


}

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

}

Answer 1

答案很简单只需在AsyncTask中执行相机操作即可。可能会有用。

@Override
     protected void onHandleIntent(Intent intent) {
     Bundle extras = intent.getExtras();
     String msg = intent.getStringExtra("message");
     GoogleCloudMessaging gcm = GoogleCloudMessaging.getInstance(this);
     String messageType = gcm.getMessageType(intent);

      if (!extras.isEmpty()) {
           if (GoogleCloudMessaging.MESSAGE_TYPE_MESSAGE.equals(messageType)) {
           System.out.println("message received");

               try {
            json = new JSONObject(msg);
            function = json.getString("function");

        } catch (JSONException e) {

            e.printStackTrace();
        }
                if (function.equals("capture")) {
            System.out.println("capture entereeeeed =====================");
            new AsyncTask<Void, Void, String>() {
               @Override
                   protected String doInBackground(Void...params) {
                  Capture cap = new Capture(getApplicationContext());
                      cap.captureNow();
                  String result = "ok";
           return result;
                    }
                  @Override
                  protected void onPostExecute(String result)  {




                    }

                }.execute();
        }

    }
}

我如何在IntentService中使用Camera API？

1 个答案: