无法在android中拍照

无法在android中拍照,android,camera,Android,Camera,我正在使用下面的类在Android中拍照,我想使用前置摄像头拍照。我已将所需权限添加到清单文件: public class CameraController extends AsyncTask{ final Context context; private boolean hasCamera; private Camera camera; private int cameraId; public CameraController(Context c

我正在使用下面的类在Android中拍照,我想使用前置摄像头拍照。我已将所需权限添加到清单文件:

public class CameraController extends AsyncTask{

    final Context context;

    private boolean hasCamera;

    private Camera camera;
    private int cameraId;

    public CameraController(Context c){
        context = c.getApplicationContext();

        if(context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)){
            cameraId = getFrontCameraId();

            if(cameraId != -1){
                hasCamera = true;
            }else{
                hasCamera = false;
            }
        }else{
            hasCamera = false;
        }
    }


    public void getCameraInstance(){
        camera = null;

        if(hasCamera){
            try{
                camera = Camera.open(cameraId);
                prepareCamera();
            }
            catch(Exception e){
                hasCamera = false;
            }
        }
    }

    public void takePicture(){
        if(hasCamera){
            camera.takePicture(null,null,mPicture);
        }
    }

    public void releaseCamera(){
        if(camera != null){
            camera.stopPreview();
            camera.release();
            camera = null;
        }
    }

    private int getFrontCameraId(){
        int camId = -1;
        int numberOfCameras = Camera.getNumberOfCameras();
        CameraInfo ci = new CameraInfo();

        for(int i = 0;i < numberOfCameras;i++){
            Camera.getCameraInfo(i,ci);
            if(ci.facing == CameraInfo.CAMERA_FACING_FRONT){
                camId = i;
            }
        }

        return camId;
    }

    private void prepareCamera(){
        SurfaceView view = new SurfaceView(context);

        try{
            camera.setPreviewDisplay(view.getHolder());
        }catch(IOException e){
            throw new RuntimeException(e);
        }

        camera.startPreview();

        Camera.Parameters params = camera.getParameters();
        params.setJpegQuality(100);

        camera.setParameters(params);
    }

    private Camera.PictureCallback mPicture = new Camera.PictureCallback(){
        @Override
        public void onPictureTaken(byte[] data, Camera camera){
            File pictureFile = getOutputMediaFile();

            if(pictureFile == null){
                Log.d("TEST", "Error creating media file, check storage permissions");
                return;
            }

            try{
                Log.d("TEST","File created");
                FileOutputStream fos = new FileOutputStream(pictureFile);
                fos.write(data);
                fos.close();
            }catch(FileNotFoundException e){
                Log.d("TEST","File not found: "+e.getMessage());
            } catch (IOException e){
                Log.d("TEST","Error accessing file: "+e.getMessage());
            }
        }
    };

    private File getOutputMediaFile(){

        File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),"MyCameraApp");

        if(!mediaStorageDir.exists()){
            if(!mediaStorageDir.mkdirs()){
                return null;
            }
        }

        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());

        File mediaFile;
        mediaFile = new File(mediaStorageDir.getPath()+File.separator+"IMG_"+timeStamp+".jpg");

        return mediaFile;
    }

    @Override
    protected Object doInBackground(Object[] params) {
        try{

            takePicture();
            return "1";
        }catch(Exception e){
            return "-1";
        }
    }
    @Override
    protected void onPostExecute(Object o) {
        super.onPostExecute(o);
        releaseCamera();

    }
}

上述代码不起作用,也没有拍摄任何照片。我调试了代码,发现没有调用onPictureTaken

试试这段代码:这是主要的活动

public class AndroidCameraExample extends Activity implements SensorEventListener,FaceDetectionListener{
    private Camera mCamera;
    private CameraPreview mPreview;
    private PictureCallback mPicture;
    private Button capture, switchCamera;
    private Context myContext;
    private LinearLayout cameraPreview;
    private boolean cameraFront = false,hasaccel,changed=false;
    SensorManager sm;
    List<Sensor> s;
    Sensor sensor;
    String photopath;
    int ax=100,ay;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
        WindowManager.LayoutParams layout = getWindow().getAttributes();
        layout.screenBrightness = 1F;
        getWindow().setAttributes(layout);
        myContext = this;
        initialize();
        hasaccel = checkaccelerometer();

    }

    private 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) {
                cameraId = i;
                cameraFront = true;
                break;
            }
        }
        return cameraId;
    }

    private int findBackFacingCamera() {
        int cameraId = -1;
        //Search for the back facing camera
        //get the number of cameras
        int numberOfCameras = Camera.getNumberOfCameras();
        //for every camera check
        for (int i = 0; i < numberOfCameras; i++) {
            CameraInfo info = new CameraInfo();
            Camera.getCameraInfo(i, info);
            if (info.facing == CameraInfo.CAMERA_FACING_BACK) {
                cameraId = i;
                cameraFront = false;
                break;
            }
        }
        return cameraId;
    }

    public void onResume() {
        super.onResume();
        if (!hasCamera(myContext)) {
            Toast toast = Toast.makeText(myContext, "Sorry, your phone does not have a camera!", Toast.LENGTH_LONG);
            toast.show();
            finish();
        }
        if (mCamera == null) {
            //if the front facing camera does not exist
            if (findFrontFacingCamera() < 0) {
                Toast.makeText(this, "No front facing camera found.", Toast.LENGTH_LONG).show();
                switchCamera.setVisibility(View.GONE);
            }       
            int cameraId = findFrontFacingCamera();
            //Mayur
            mCamera = Camera.open((cameraId));

        //  mCamera.setFaceDetectionListener(this);
        //  mCamera.startFaceDetection();
            setCameraDisplayOrientation(this, cameraId, mCamera);
            mPicture = getPictureCallback();
            mPreview.refreshCamera(mCamera);
        }
    }

    public void initialize() {
        cameraPreview = (LinearLayout) findViewById(R.id.camera_preview);
        mPreview = new CameraPreview(myContext, mCamera);
        cameraPreview.addView(mPreview);

        capture = (Button) findViewById(R.id.button_capture);
        capture.setOnClickListener(captrureListener);

        switchCamera = (Button) findViewById(R.id.button_ChangeCamera);
        switchCamera.setOnClickListener(switchCameraListener);
    }

    OnClickListener switchCameraListener = new OnClickListener() {
        @Override
        public void onClick(View v) {
            //get the number of cameras
            int camerasNumber = Camera.getNumberOfCameras();
            if (camerasNumber > 1) {
                //release the old camera instance
                //switch camera, from the front and the back and vice versa

                releaseCamera();
                chooseCamera();
            } else {
                Toast toast = Toast.makeText(myContext, "Sorry, your phone has only one camera!", Toast.LENGTH_LONG);
                toast.show();
            }
        }
    };

    public void chooseCamera() {
        //if the camera preview is the front
        if (cameraFront) {
            int cameraId = findBackFacingCamera();
            if (cameraId >= 0) {
                //open the backFacingCamera
                //set a picture callback
                //refresh the preview

                mCamera = Camera.open(cameraId);                
                mPicture = getPictureCallback();            
                mPreview.refreshCamera(mCamera);
            }
        } else {
            int cameraId = findFrontFacingCamera();
            if (cameraId >= 0) {
                //open the backFacingCamera
                //set a picture callback
                //refresh the preview

                mCamera = Camera.open(cameraId);
                mPicture = getPictureCallback();
                mPreview.refreshCamera(mCamera);
            }
        }
    }

    @Override
    protected void onPause() {
        super.onPause();
        //when on Pause, release camera in order to be used from other applications
        releaseCamera();
    }

    private boolean hasCamera(Context context) {
        //check if the device has camera
        if (context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)) {
            return true;
        } else {
            return false;
        }
    }

    private PictureCallback getPictureCallback() {
        PictureCallback picture = new PictureCallback() {

            @Override
            public void onPictureTaken(byte[] data, Camera camera) {
                //make a new picture file
                File pictureFile = getOutputMediaFile();
                // Location of stored image
                Log.d("Mayur", "Picture: "+pictureFile);
                Log.d("Mayur","Data: "+data);
                if (pictureFile == null) {
                    return;
                }
                try {
                    //check orientation and rotate if necessary

                    //write the file
                    while(!changed)
                    {
                    Log.d("Parth", "X: "+ax);
                    }
                    int rotate=-90;
                /*  if((ax<=5 && ax>=-1) && (ay>=6 && ay<=9))
                    {
                        rotate=-90;
                    }
                    else if((ax<=9 && ax>=6) && (ay>=-1 && ay<=5))
                    {
                        rotate=-90;
                    }
                    else if((ax<=-6 && ax>=-9) && (ay>=-1 && ay<=5))
                    {
                        rotate = -180;
                    }
                    else if((ax<=5 && ax>=-1) && (ay>=-9 && ay<=-6))
                    {
                        rotate = 90;
                    }
                    */
                    Log.d("Parth", "X: "+ax+" Y:"+ay);
                    Matrix matrix = new Matrix();
                    if(android.os.Build.VERSION.SDK_INT>13 )
                    {
                        float[] mirrorY = { -1, 0, 0, 0, 1, 0, 0, 0, 1};
                        Matrix matrixMirrorY = new Matrix();
                        matrixMirrorY.setValues(mirrorY);

                        matrix.postConcat(matrixMirrorY);

                        matrix.preRotate(rotate);

                    }

                    Bitmap bmp = BitmapFactory.decodeByteArray(data, 0, data.length);
                    int i = ExifInterface.ORIENTATION_FLIP_HORIZONTAL;
                    bmp = Bitmap.createBitmap(bmp,0,0,bmp.getWidth(),bmp.getHeight(),matrix,true);
                    FileOutputStream fos = new FileOutputStream(pictureFile);
                    bmp.compress(Bitmap.CompressFormat.JPEG, 85, fos);
                    photopath = pictureFile.getAbsolutePath();
                    fos.flush();
                    fos.close();
                    bmp.recycle();
                    //Toast toast = Toast.makeText(myContext, "Picture saved: " + pictureFile.getName(), Toast.LENGTH_LONG);
                    //toast.show();
                    sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(pictureFile)));
                    Intent intent = new Intent(myContext, LayoutTest1Activity.class);
                    intent.putExtra("path", photopath);
                    startActivity(intent);
                    finish();

                } catch (FileNotFoundException e) {
                } catch (IOException e) {
                }

                //refresh camera to continue preview
                mPreview.refreshCamera(mCamera);
            }
        };
        return picture;
    }

    protected void checkorientation() {
        // TODO Auto-generated method stub
        sensor = sm.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
        sm.registerListener(this, sensor,SensorManager.SENSOR_DELAY_FASTEST);

    }

    OnClickListener captrureListener = new OnClickListener() {
        @Override
        public void onClick(View v) {
            //Mayur
            checkorientation();
            Camera.Parameters params=mCamera.getParameters();
            List<Size> sizes =params.getSupportedPictureSizes();
            Size mSize=null;
            int temp=0;
//          for(Size size:sizes)
//          {
//              mSize=size;
//              Log.d("Mayur", "H: "+mSize.height+" W: "+mSize.width);
//          }

            mSize=sizes.get(0); //taking largest resolution

            Log.d("Mayur", "Loaded with  H: "+mSize.height+"W: "+mSize.width);
            params.setPictureSize(mSize.width, mSize.height);
            mCamera.setParameters(params);

            //
            mCamera.takePicture(null, null, mPicture);

        }


    };
    private boolean checkaccelerometer() {
        sm = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
        s = new ArrayList<Sensor>();
        s = sm.getSensorList(Sensor.TYPE_ACCELEROMETER);
        if(s.size()>0)
        {
            Toast.makeText(myContext, "has accelerometer", Toast.LENGTH_SHORT).show();
            return true;
        }
        return false;
        // TODO Auto-generated method stub
    }
    //make picture and save to a folder
    private static File getOutputMediaFile() {
        //make a new file directory inside the "sdcard" folder
        File mediaStorageDir = new File(Environment.getExternalStorageDirectory().getAbsolutePath()+"/Creaa");
        mediaStorageDir.mkdirs();
        //if this "Creaa Camera folder does not exist
        if (!mediaStorageDir.exists()) {
            //if you cannot make this folder return
            if (!mediaStorageDir.mkdirs()) {
                return null;
            }
        }

        //take the current timeStamp
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
        File mediaFile;
        //and make a media file:
        mediaFile = new File(mediaStorageDir.getPath() + File.separator + "mypic_" + timeStamp + ".jpg");
        return mediaFile;
    }

    private void releaseCamera() {
        // stop and release camera
        if (mCamera != null) {
            mCamera.release();
            mCamera = null;
        }
    }

    @Override
    public void onSensorChanged(SensorEvent event) {
        // TODO Auto-generated method stub
        ax = (int) event.values[0];
        ay  = (int) event.values[1];
        sm.unregisterListener(this);
        Toast.makeText(myContext, "X : "+ax+" Y: "+ay, Toast.LENGTH_SHORT).show();
        changed=true;
    }

    @Override
    public void onAccuracyChanged(Sensor sensor, int accuracy) {
        // TODO Auto-generated method stub

    }

    public static void setCameraDisplayOrientation(Activity activity,
             int cameraId, android.hardware.Camera camera) {
         android.hardware.Camera.CameraInfo info =
                 new android.hardware.Camera.CameraInfo();
         android.hardware.Camera.getCameraInfo(cameraId, info);
         int rotation = activity.getWindowManager().getDefaultDisplay()
                 .getRotation();
         int degrees = 0;
         switch (rotation) {
             case Surface.ROTATION_0: degrees = 0; break;
             case Surface.ROTATION_90: degrees = 90; break;
             case Surface.ROTATION_180: degrees = 180; break;
             case Surface.ROTATION_270: degrees = 270; break;
         }

         int result;
         if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
             result = (info.orientation + degrees) % 360;
             result = (360 - result) % 360;  // compensate the mirror
         } else {  // back-facing
             result = (info.orientation - degrees + 360) % 360;
         }
         Log.d("Parth", "Result : "+result);
         camera.setDisplayOrientation(result);
     }

    @Override
    public void onFaceDetection(Face[] faces, Camera camera) {
        // TODO Auto-generated method stub
        Toast.makeText(this, "facedeteted", Toast.LENGTH_SHORT).show();
        if(faces.length>0)
        Log.d("Parth", "mouth:"+faces[0].mouth.x+"\nrect :"+faces[0].rect.bottom);
    }


}

此代码用于直接启动前摄像头。使用以上两个类

也许这会对您有所帮助,您调用
camera.takePicture()
太早了。限制条件是只有在预览实际开始后才允许这样做(这意味着对于某些设备,我们必须在调用
startPreview()
后等待300毫秒)。
public class AndroidCameraExample extends Activity implements SensorEventListener,FaceDetectionListener{
    private Camera mCamera;
    private CameraPreview mPreview;
    private PictureCallback mPicture;
    private Button capture, switchCamera;
    private Context myContext;
    private LinearLayout cameraPreview;
    private boolean cameraFront = false,hasaccel,changed=false;
    SensorManager sm;
    List<Sensor> s;
    Sensor sensor;
    String photopath;
    int ax=100,ay;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
        WindowManager.LayoutParams layout = getWindow().getAttributes();
        layout.screenBrightness = 1F;
        getWindow().setAttributes(layout);
        myContext = this;
        initialize();
        hasaccel = checkaccelerometer();

    }

    private 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) {
                cameraId = i;
                cameraFront = true;
                break;
            }
        }
        return cameraId;
    }

    private int findBackFacingCamera() {
        int cameraId = -1;
        //Search for the back facing camera
        //get the number of cameras
        int numberOfCameras = Camera.getNumberOfCameras();
        //for every camera check
        for (int i = 0; i < numberOfCameras; i++) {
            CameraInfo info = new CameraInfo();
            Camera.getCameraInfo(i, info);
            if (info.facing == CameraInfo.CAMERA_FACING_BACK) {
                cameraId = i;
                cameraFront = false;
                break;
            }
        }
        return cameraId;
    }

    public void onResume() {
        super.onResume();
        if (!hasCamera(myContext)) {
            Toast toast = Toast.makeText(myContext, "Sorry, your phone does not have a camera!", Toast.LENGTH_LONG);
            toast.show();
            finish();
        }
        if (mCamera == null) {
            //if the front facing camera does not exist
            if (findFrontFacingCamera() < 0) {
                Toast.makeText(this, "No front facing camera found.", Toast.LENGTH_LONG).show();
                switchCamera.setVisibility(View.GONE);
            }       
            int cameraId = findFrontFacingCamera();
            //Mayur
            mCamera = Camera.open((cameraId));

        //  mCamera.setFaceDetectionListener(this);
        //  mCamera.startFaceDetection();
            setCameraDisplayOrientation(this, cameraId, mCamera);
            mPicture = getPictureCallback();
            mPreview.refreshCamera(mCamera);
        }
    }

    public void initialize() {
        cameraPreview = (LinearLayout) findViewById(R.id.camera_preview);
        mPreview = new CameraPreview(myContext, mCamera);
        cameraPreview.addView(mPreview);

        capture = (Button) findViewById(R.id.button_capture);
        capture.setOnClickListener(captrureListener);

        switchCamera = (Button) findViewById(R.id.button_ChangeCamera);
        switchCamera.setOnClickListener(switchCameraListener);
    }

    OnClickListener switchCameraListener = new OnClickListener() {
        @Override
        public void onClick(View v) {
            //get the number of cameras
            int camerasNumber = Camera.getNumberOfCameras();
            if (camerasNumber > 1) {
                //release the old camera instance
                //switch camera, from the front and the back and vice versa

                releaseCamera();
                chooseCamera();
            } else {
                Toast toast = Toast.makeText(myContext, "Sorry, your phone has only one camera!", Toast.LENGTH_LONG);
                toast.show();
            }
        }
    };

    public void chooseCamera() {
        //if the camera preview is the front
        if (cameraFront) {
            int cameraId = findBackFacingCamera();
            if (cameraId >= 0) {
                //open the backFacingCamera
                //set a picture callback
                //refresh the preview

                mCamera = Camera.open(cameraId);                
                mPicture = getPictureCallback();            
                mPreview.refreshCamera(mCamera);
            }
        } else {
            int cameraId = findFrontFacingCamera();
            if (cameraId >= 0) {
                //open the backFacingCamera
                //set a picture callback
                //refresh the preview

                mCamera = Camera.open(cameraId);
                mPicture = getPictureCallback();
                mPreview.refreshCamera(mCamera);
            }
        }
    }

    @Override
    protected void onPause() {
        super.onPause();
        //when on Pause, release camera in order to be used from other applications
        releaseCamera();
    }

    private boolean hasCamera(Context context) {
        //check if the device has camera
        if (context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)) {
            return true;
        } else {
            return false;
        }
    }

    private PictureCallback getPictureCallback() {
        PictureCallback picture = new PictureCallback() {

            @Override
            public void onPictureTaken(byte[] data, Camera camera) {
                //make a new picture file
                File pictureFile = getOutputMediaFile();
                // Location of stored image
                Log.d("Mayur", "Picture: "+pictureFile);
                Log.d("Mayur","Data: "+data);
                if (pictureFile == null) {
                    return;
                }
                try {
                    //check orientation and rotate if necessary

                    //write the file
                    while(!changed)
                    {
                    Log.d("Parth", "X: "+ax);
                    }
                    int rotate=-90;
                /*  if((ax<=5 && ax>=-1) && (ay>=6 && ay<=9))
                    {
                        rotate=-90;
                    }
                    else if((ax<=9 && ax>=6) && (ay>=-1 && ay<=5))
                    {
                        rotate=-90;
                    }
                    else if((ax<=-6 && ax>=-9) && (ay>=-1 && ay<=5))
                    {
                        rotate = -180;
                    }
                    else if((ax<=5 && ax>=-1) && (ay>=-9 && ay<=-6))
                    {
                        rotate = 90;
                    }
                    */
                    Log.d("Parth", "X: "+ax+" Y:"+ay);
                    Matrix matrix = new Matrix();
                    if(android.os.Build.VERSION.SDK_INT>13 )
                    {
                        float[] mirrorY = { -1, 0, 0, 0, 1, 0, 0, 0, 1};
                        Matrix matrixMirrorY = new Matrix();
                        matrixMirrorY.setValues(mirrorY);

                        matrix.postConcat(matrixMirrorY);

                        matrix.preRotate(rotate);

                    }

                    Bitmap bmp = BitmapFactory.decodeByteArray(data, 0, data.length);
                    int i = ExifInterface.ORIENTATION_FLIP_HORIZONTAL;
                    bmp = Bitmap.createBitmap(bmp,0,0,bmp.getWidth(),bmp.getHeight(),matrix,true);
                    FileOutputStream fos = new FileOutputStream(pictureFile);
                    bmp.compress(Bitmap.CompressFormat.JPEG, 85, fos);
                    photopath = pictureFile.getAbsolutePath();
                    fos.flush();
                    fos.close();
                    bmp.recycle();
                    //Toast toast = Toast.makeText(myContext, "Picture saved: " + pictureFile.getName(), Toast.LENGTH_LONG);
                    //toast.show();
                    sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.fromFile(pictureFile)));
                    Intent intent = new Intent(myContext, LayoutTest1Activity.class);
                    intent.putExtra("path", photopath);
                    startActivity(intent);
                    finish();

                } catch (FileNotFoundException e) {
                } catch (IOException e) {
                }

                //refresh camera to continue preview
                mPreview.refreshCamera(mCamera);
            }
        };
        return picture;
    }

    protected void checkorientation() {
        // TODO Auto-generated method stub
        sensor = sm.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
        sm.registerListener(this, sensor,SensorManager.SENSOR_DELAY_FASTEST);

    }

    OnClickListener captrureListener = new OnClickListener() {
        @Override
        public void onClick(View v) {
            //Mayur
            checkorientation();
            Camera.Parameters params=mCamera.getParameters();
            List<Size> sizes =params.getSupportedPictureSizes();
            Size mSize=null;
            int temp=0;
//          for(Size size:sizes)
//          {
//              mSize=size;
//              Log.d("Mayur", "H: "+mSize.height+" W: "+mSize.width);
//          }

            mSize=sizes.get(0); //taking largest resolution

            Log.d("Mayur", "Loaded with  H: "+mSize.height+"W: "+mSize.width);
            params.setPictureSize(mSize.width, mSize.height);
            mCamera.setParameters(params);

            //
            mCamera.takePicture(null, null, mPicture);

        }


    };
    private boolean checkaccelerometer() {
        sm = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
        s = new ArrayList<Sensor>();
        s = sm.getSensorList(Sensor.TYPE_ACCELEROMETER);
        if(s.size()>0)
        {
            Toast.makeText(myContext, "has accelerometer", Toast.LENGTH_SHORT).show();
            return true;
        }
        return false;
        // TODO Auto-generated method stub
    }
    //make picture and save to a folder
    private static File getOutputMediaFile() {
        //make a new file directory inside the "sdcard" folder
        File mediaStorageDir = new File(Environment.getExternalStorageDirectory().getAbsolutePath()+"/Creaa");
        mediaStorageDir.mkdirs();
        //if this "Creaa Camera folder does not exist
        if (!mediaStorageDir.exists()) {
            //if you cannot make this folder return
            if (!mediaStorageDir.mkdirs()) {
                return null;
            }
        }

        //take the current timeStamp
        String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
        File mediaFile;
        //and make a media file:
        mediaFile = new File(mediaStorageDir.getPath() + File.separator + "mypic_" + timeStamp + ".jpg");
        return mediaFile;
    }

    private void releaseCamera() {
        // stop and release camera
        if (mCamera != null) {
            mCamera.release();
            mCamera = null;
        }
    }

    @Override
    public void onSensorChanged(SensorEvent event) {
        // TODO Auto-generated method stub
        ax = (int) event.values[0];
        ay  = (int) event.values[1];
        sm.unregisterListener(this);
        Toast.makeText(myContext, "X : "+ax+" Y: "+ay, Toast.LENGTH_SHORT).show();
        changed=true;
    }

    @Override
    public void onAccuracyChanged(Sensor sensor, int accuracy) {
        // TODO Auto-generated method stub

    }

    public static void setCameraDisplayOrientation(Activity activity,
             int cameraId, android.hardware.Camera camera) {
         android.hardware.Camera.CameraInfo info =
                 new android.hardware.Camera.CameraInfo();
         android.hardware.Camera.getCameraInfo(cameraId, info);
         int rotation = activity.getWindowManager().getDefaultDisplay()
                 .getRotation();
         int degrees = 0;
         switch (rotation) {
             case Surface.ROTATION_0: degrees = 0; break;
             case Surface.ROTATION_90: degrees = 90; break;
             case Surface.ROTATION_180: degrees = 180; break;
             case Surface.ROTATION_270: degrees = 270; break;
         }

         int result;
         if (info.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
             result = (info.orientation + degrees) % 360;
             result = (360 - result) % 360;  // compensate the mirror
         } else {  // back-facing
             result = (info.orientation - degrees + 360) % 360;
         }
         Log.d("Parth", "Result : "+result);
         camera.setDisplayOrientation(result);
     }

    @Override
    public void onFaceDetection(Face[] faces, Camera camera) {
        // TODO Auto-generated method stub
        Toast.makeText(this, "facedeteted", Toast.LENGTH_SHORT).show();
        if(faces.length>0)
        Log.d("Parth", "mouth:"+faces[0].mouth.x+"\nrect :"+faces[0].rect.bottom);
    }


}
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
    private SurfaceHolder mHolder;
    private Camera mCamera;

    public CameraPreview(Context context, Camera camera) {
        super(context);
        mCamera = camera;
        mHolder = getHolder();
        mHolder.addCallback(this);
        // deprecated setting, but required on Android versions prior to 3.0
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }

    public void surfaceCreated(SurfaceHolder holder) {
        try {
            // create the surface and start camera preview
            if (mCamera == null) {
                mCamera.setPreviewDisplay(holder);
                mCamera.startPreview();
            }
        } catch (IOException e) {
            Log.d(VIEW_LOG_TAG, "Error setting camera preview: " + e.getMessage());
        }
    }

    public void refreshCamera(Camera camera) {
        if (mHolder.getSurface() == null) {
            // preview surface does not exist
            return;
        }
        // stop preview before making changes
        try {
            mCamera.stopPreview();
        } catch (Exception e) {
            // ignore: tried to stop a non-existent preview
        }
        // set preview size and make any resize, rotate or
        // reformatting changes here
        // start preview with new settings
        setCamera(camera);
        try {
            mCamera.setPreviewDisplay(mHolder);
            mCamera.startPreview();
        } catch (Exception e) {
            Log.d(VIEW_LOG_TAG, "Error starting camera preview: " + e.getMessage());
        }
    }

    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
        // If your preview can change or rotate, take care of those events here.
        // Make sure to stop the preview before resizing or reformatting it.
        refreshCamera(mCamera);
    }

    public void setCamera(Camera camera) {
        //method to set a camera instance
        mCamera = camera;
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        // TODO Auto-generated method stub
        // mCamera.release();

    }
}