3

私はカメラから写真を提供しようとしています。

@Override
public void onCreate() {
    super.onCreate();
    //android.os.Debug.waitForDebugger();

    myCamera=Camera.open();


      SurfaceView dummy=new SurfaceView(getApplicationContext());
    try {
        if(myCamera!=null)
        {
            myCamera.setPreviewDisplay(dummy.getHolder());
            myCamera.setPreviewCallback(this);
            Log.i(TAG,"myCamera is not null");
        }
            getFrames();

    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
        Log.e(TAG, "setPreviewDisplay " + e);
    }    
    myCamera.startPreview(); 
}


    public void getFrames() {

        new Thread(new Runnable() {

            public void run() {

                    while(flag)
                    {
                        Log.i(TAG, "getFrames");
                        try{

                            //method();
                        takePictureNoPreview();
                        Thread.sleep(54);

                        } catch (Exception e) {
                            Log.e(TAG, "getFrames thread error: " + e);
                        }
                    }
                     myCamera.release();  

            }
        }).start();
    }


public void takePictureNoPreview(){
            try{
              Log.i(TAG,"takePictureNoPreview");
              myCamera.takePicture(null, null, getJpegCallback())
            } catch (Exception e) {
                Log.e(TAG, "takePictureNoPreview " + e);
            }


     private PictureCallback getJpegCallback(){
                PictureCallback jpeg=new PictureCallback() {   
                  @Override
                  public void onPictureTaken(byte[] data, Camera camera) {
                    try {
                      Log.i(TAG,"getJpegCallback");
                      FileOutputStream(String.format("/sdcard/RealSpeaker/%d.jpg", System.currentTimeMillis()));
                      FileOutputStream os = new FileOutputStream(String.format("/sdcard/Sample/%d.jpg", System.currentTimeMillis()));
                         os.write(data);
                         os.close();
                    }  catch (IOException e) {
                      //do something about it
                    }
                  }
                };
                return jpeg;

              }

問題は、メソッド getJpegCallback が正しくないことです: (フォルダにログと画像がありません)ю アプリケーションをデバッグしているとき、TAG - getJpegCallbackは LogCat に表示されませんが、TAG takePictureNoPreview は表示されます。そして、アプリケーションを閉じた後、カメラは許可しません(今は問題ありません)。どうしたの?

4

6 に答える 6

3

EyeSpyの開発中にこの問題に直面しました。アプリがバックグラウンドでもフォアグラウンドでも画像をキャプチャしたかった。数週間試しましたが、うまくいきませんでした。カメラを使用して写真をキャプチャすると、そのプレビューが表示されます。

ドキュメントから(5. と 6.) また、SurfaceViewを使用してプレビューを表示する必要があります。

アプリを閉じるか、アプリがバックグラウンドになると、表面SurfaceViewが破壊されます。だからこそ無理だと思います。

他の方法を見つけた場合は、ここに投稿してください。

これがあなたを助けることを願っています..

于 2013-09-05T11:34:34.777 に答える
2

SurfaceHolderAPI 11 以降、 yourの を使用する代わりに、 を使用SurfaceViewできますSurfaceTextureCamera.setPreviewTexture次に、代わりに を使用して設定しますCamera.setPreviewDisplay

さまざまなデバイスのサービスでうまくいきました。

この回答とこの回答では、この点について説明しています。

于 2014-06-16T07:29:03.150 に答える
0
public class TakePicture extends Activity implements SurfaceHolder.Callback {
    // a variable to store a reference to the Image View at the main.xml file
    // private ImageView iv_image;
    // a variable to store a reference to the Surface View at the main.xml file
    private SurfaceView sv;

    // a bitmap to display the captured image
    private Bitmap bmp;
    FileOutputStream fo;

    // Camera variables
    // a surface holder
    private SurfaceHolder sHolder;
    // a variable to control the camera
    private Camera mCamera;
    // the camera parameters
    private Parameters parameters;
    private String FLASH_MODE;
    private boolean isFrontCamRequest = false;
    private Camera.Size pictureSize;

    /** Called when the activity is first created. */
    @SuppressWarnings("deprecation")
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // check if this device has a camera
        if (checkCameraHardware(getApplicationContext())) 
        {
            // get the Image View at the main.xml file
            // iv_image = (ImageView) findViewById(R.id.imageView);

            // get the Surface View at the main.xml file
            Bundle extras = getIntent().getExtras();
            String flash_mode = extras.getString("FLASH");
            FLASH_MODE = flash_mode;
            boolean front_cam_req = extras.getBoolean("Front_Request");
            isFrontCamRequest = true;


            System.out.println("front_cam_req :"+front_cam_req);
            sv = (SurfaceView) findViewById(R.id.camera_preview);

            // Get a surface
            sHolder = sv.getHolder();

            // add the callback interface methods defined below as the Surface
            // View
            // callbacks
            sHolder.addCallback(this);

            // tells Android that this surface will have its data constantly
            // replaced
            if (Build.VERSION.SDK_INT < 11)
                sHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

        }
        else {
            // display in long period of time
            Toast.makeText(getApplicationContext(),
                    "Your Device dosen't have a Camera !", Toast.LENGTH_LONG)
                    .show();
        }

    }

    /** Check if this device has a camera */
    private boolean checkCameraHardware(Context context) {
        if (context.getPackageManager().hasSystemFeature(
                PackageManager.FEATURE_CAMERA)) {
            // this device has a camera
            return true;
        } else {
            // no camera on this device
            return false;
        }
    }

    /** Check if this device has front camera */
    private boolean checkFrontCamera(Context context) 
    {
        if (context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA_FRONT)) 
        {
            // this device has front camera
            return true;
        } 
        else
        {
            // no front camera on this device
            return false;
        }
    }

    public static Camera getCameraInstance()
    {
        Camera c = null;
        try {
            c = Camera.open(); // attempt to get a Camera instance
        } catch (Exception e) {
            // Camera is not available (in use or does not exist)
        }
        return c; // returns null if camera is unavailable
    }

    @Override
    public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
        // get camera parameters
        if (mCamera != null) {
            parameters = mCamera.getParameters();
            if (FLASH_MODE == null || FLASH_MODE.isEmpty()) {
                FLASH_MODE = "auto";
            }
            parameters.setFlashMode(FLASH_MODE);
            pictureSize = getBiggesttPictureSize(parameters);
            if (pictureSize != null)
                parameters
                        .setPictureSize(pictureSize.width, pictureSize.height);
            // set camera parameters
            mCamera.setParameters(parameters);

            mCamera.startPreview();

            // sets what code should be executed after the picture is taken
            Camera.PictureCallback mCall = new Camera.PictureCallback() {
                @Override
                public void onPictureTaken(byte[] data, Camera camera) {
                    // decode the data obtained by the camera into a Bitmap
                    Log.d("ImageTakin", "Done");

                    bmp = BitmapFactory.decodeByteArray(data, 0, data.length);
                    ByteArrayOutputStream bytes = new ByteArrayOutputStream();
                    if (bmp != null)
                        bmp.compress(Bitmap.CompressFormat.JPEG, 100, bytes);

                    File imagesFolder = new File(
                            Environment.getExternalStorageDirectory(),
                            "OneSheeld");
                    if (!imagesFolder.exists())
                        imagesFolder.mkdirs(); // <----
                    File image = new File(imagesFolder,
                            System.currentTimeMillis() + ".jpg");

                    // write the bytes in file
                    try {
                        fo = new FileOutputStream(image);
                    } catch (FileNotFoundException e) {
                        // TODO Auto-generated catch block
                    }
                    try {
                        fo.write(bytes.toByteArray());
                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                    }

                    // remember close de FileOutput
                    try {
                        fo.close();
                        sendBroadcast(new Intent(Intent.ACTION_MEDIA_MOUNTED,
                                Uri.parse("file://"
                                        + Environment
                                                .getExternalStorageDirectory())));

                    } catch (IOException e) {
                        // TODO Auto-generated catch block
                    }
                    if (mCamera != null) {
                        mCamera.stopPreview();
                        // release the camera
                        mCamera.release();
                    }
                    Toast.makeText(getApplicationContext(),
                            "Your Picture has been taken !", Toast.LENGTH_LONG)
                            .show();
                    if (bmp != null) {
                        bmp.recycle();
                        bmp = null;
                        System.gc();
                    }
                    TakePicture.this.finish();

                }
            };

            mCamera.takePicture(null, null, mCall);
        }
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder)
    {
        // The Surface has been created, acquire the camera and tell it where
        // to draw the preview.
        if (isFrontCamRequest)
        {

            //Toast.makeText(getApplicationContext()," isFrontCamRequest()",Toast.LENGTH_LONG).show();

            System.out.println("isFrontCamRequest 1");
            // set flash 0ff
            FLASH_MODE = "off";
            // only for gingerbread and newer versions
            if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.GINGERBREAD)
            {
                System.out.println("isFrontCamRequest 2");
                mCamera = openFrontFacingCameraGingerbread();
                try {
                    mCamera.setPreviewDisplay(holder);

                } catch (IOException exception) {
                    mCamera = null;
                    Toast.makeText(getApplicationContext(),"API dosen't support front camera",Toast.LENGTH_LONG).show();
                    TakePicture.this.finish();
                }
            }
            else 
            {
                System.out.println("isFrontCamRequest 3");
                if (checkFrontCamera(getApplicationContext()))
                {
                    mCamera = openFrontFacingCameraGingerbread();
                    try
                    {
                        mCamera.setPreviewDisplay(holder);

                    }
                    catch (IOException exception)
                    {
                        mCamera = null;
                        Toast.makeText(getApplicationContext(),
                                "API dosen't support front camera",
                                Toast.LENGTH_LONG).show();
                        TakePicture.this.finish();
                    }
                }/*
                 * else { // API dosen't support front camera or no front camera
                 * Log.d("Camera",
                 * "API dosen't support front camera or no front camera");
                 * Toast.makeText( getApplicationContext(),
                 * "API dosen't support front camera or no front camera",
                 * Toast.LENGTH_LONG).show();
                 * 
                 * finish(); }
                 */

            }
        } 
        else
        {
            System.out.println("isFrontCamRequest 4");
            mCamera = getCameraInstance();
            try
            {
                mCamera.setPreviewDisplay(holder);

            } 
            catch (Exception exception) {
                mCamera = null;
            }
        }

    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        // stop the preview
        /*
         * mCamera.stopPreview(); // release the camera mCamera.release();
         */
        // unbind the camera from this object
        mCamera = null;
    }

    private Camera openFrontFacingCameraGingerbread() {
        int cameraCount = 0;
        Camera cam = null;
        Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
        cameraCount = Camera.getNumberOfCameras();
        for (int camIdx = 0; camIdx < cameraCount; camIdx++) {
            Camera.getCameraInfo(camIdx, cameraInfo);
            if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
                try {
                    cam = Camera.open(camIdx);
                } catch (RuntimeException e) {
                    Log.e("Camera",
                            "Camera failed to open: " + e.getLocalizedMessage());
                    Toast.makeText(getApplicationContext(),
                            "Front Camera failed to open", Toast.LENGTH_LONG)
                            .show();
                }
            }
        }
        return cam;
    }

    @Override
    protected void onDestroy() {
        Intent intent = new Intent("custom-event-name");
        // You can also include some extra data.
        intent.putExtra("message", "This is my message!");
        LocalBroadcastManager.getInstance(this).sendBroadcast(intent);

        super.onDestroy();
    }

    private Camera.Size getBiggesttPictureSize(Camera.Parameters parameters) {
        Camera.Size result = null;

        for (Camera.Size size : parameters.getSupportedPictureSizes()) {
            if (result == null) {
                result = size;
            } else {
                int resultArea = result.width * result.height;
                int newArea = size.width * size.height;

                if (newArea > resultArea) {
                    result = size;
                }
            }
        }

        return (result);
    }
}
于 2014-12-06T06:13:42.797 に答える
-1

これを試すことができます

Intent translucent = new Intent(getApplication(),
                                TakePicture.class);
                        translucent.putExtra("FLASH", "on");
                        startActivity(translucent); 
                      Toast.makeText(getApplicationContext(), "Started Capture", 500).show();




 <SurfaceView
    android:id="@+id/camera_preview"
    android:layout_width="1dp"
    android:layout_height="1dp" />

<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
    <uses-permission android:name="android.permission.READ_PHONE_STATE"/>

    <uses-permission android:name="android.permission.RECORD_VIDEO"/>


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

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



    <uses-feature android:name="android.hardware.camera.front" android:required="false" />

これを実行してください。それが役に立てば幸い。

于 2014-12-06T06:23:57.040 に答える