1
Ich versuche eine Android-Anwendung zu erstellen, die im Hintergrund Bilder aufnehmen kann, sobald der Dienst gestartet wird. Ich bin in der Lage, es zu erfassen und auf SD-Karte zu speichern, aber das Bild ist etwas dunkel und ich kann das Problem nicht verfolgen. Was könnten die Möglichkeiten sein?Android Kamera im Hintergrund
Aufgenommene Bild: http://imgur.com/8onjW60
public class MyService extends Service {
Camera mCamera;
public String imageEncodeString,imageName;
public Bitmap bitmap;
public File file;
Camera.PictureCallback mPictureCallback = new Camera.PictureCallback() {
@Override
public void onPictureTaken(byte[] data, Camera camera) {
if (data != null) {
bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
if (bitmap != null) {
imageName = String.valueOf(System.currentTimeMillis() + ".jpg");
File basedir = new File(Environment.getExternalStorageDirectory() + "/dirr");
file = new File(Environment.getExternalStorageDirectory() + "/dirr" + File.separator + imageName);
if (!basedir.isDirectory()) {
basedir.mkdirs();
}
try {
file.createNewFile();
FileOutputStream otstream = new FileOutputStream(file);
bitmap.compress(Bitmap.CompressFormat.JPEG,100,otstream);
byte[] img =new byte[0];
otstream.write(img);
otstream.flush();
otstream.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
mCamera.startPreview();
}
}
};
public MyService() {
}
public IBinder onBind(Intent intent) {
// TODO: Return the communication channel to the service.
throw new UnsupportedOperationException("Not yet implemented");
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
Toast.makeText(MyService.this, "Starting Service...", Toast.LENGTH_SHORT).show();
Log.d("TAG", "======= service in onStartCommand");
if (checkCameraHardware(this)) {
mCamera = getCameraInstance();
if (mCamera != null) {
SurfaceView sv = new SurfaceView(this);
WindowManager wm = (WindowManager) getSystemService(Context.WINDOW_SERVICE);
WindowManager.LayoutParams params = new WindowManager.LayoutParams(1, 1,
WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY,
WindowManager.LayoutParams.FLAG_WATCH_OUTSIDE_TOUCH,
PixelFormat.TRANSPARENT);
params.alpha = 0;
SurfaceHolder sh = sv.getHolder();
sv.setZOrderOnTop(true);
sh.setFormat(PixelFormat.TRANSPARENT);
sh.addCallback(new SurfaceHolder.Callback() {
@Override
public void surfaceCreated(SurfaceHolder holder) {
Camera.Parameters parameters = mCamera.getParameters();
parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
parameters.setSceneMode(Camera.Parameters.SCENE_MODE_AUTO);
parameters.setWhiteBalance(Camera.Parameters.WHITE_BALANCE_AUTO);
mCamera.setParameters(parameters);
Camera.Parameters p = mCamera.getParameters();
List<Camera.Size> listSize;
listSize = p.getSupportedPreviewSizes();
Camera.Size mPreviewSize = listSize.get(2);
Log.v("TAG", "preview width = " + mPreviewSize.width
+ " preview height = " + mPreviewSize.height);
p.setPreviewSize(mPreviewSize.width, mPreviewSize.height);
listSize = p.getSupportedPictureSizes();
Camera.Size mPictureSize = listSize.get(2);
Log.v("TAG", "capture width = " + mPictureSize.width
+ " capture height = " + mPictureSize.height);
p.setPictureSize(mPictureSize.width, mPictureSize.height);
mCamera.setParameters(p);
try {
mCamera.setPreviewDisplay(holder);
} catch (IOException e) {
e.printStackTrace();
}
// mCamera.startPreview();
// mCamera.takePicture(null, null, mPictureCallback); // used to takePicture.
// Log.d("TAG", "========= Capturing Started");
// mCamera.stopPreview();
// mCamera.release();
// Log.d("TAG", "========== Capturing finished.");
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
mCamera.stopPreview();
mCamera.release();
}
});
wm.addView(sv, params);
} else {
Log.d("TAG", "==== get Camera from service failed");
}
}else {
Log.d("TAG", "==== There is no camera hardware on device.");
}
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
Log.d("TAG", "========= Capturing Started");
mCamera.startPreview();
mCamera.takePicture(null, null, mPictureCallback);
Vibrator vibrator = (Vibrator)getSystemService(Context.VIBRATOR_SERVICE);
vibrator.vibrate(1000);
Log.d("TAG", "========== Capturing finished.");
}
}, 5000);
return super.onStartCommand(intent, flags, startId);
}
@Override
public void onCreate() {
super.onCreate();
}
@Override
public void onDestroy() {
Toast.makeText(MyService.this, "Service Stopped...", Toast.LENGTH_SHORT).show();
}
public static boolean checkCameraHardware(Context context) {
if (context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)) {
return true;
} else {
return false;
}
}
public static Camera getCameraInstance() {
Camera c = null;
try {
c = Camera.open();
} catch (Exception e) {
Log.d("TAG", "Open camera failed: " + e);
}
return c;
}
}