3

我正在尝试将图片从相机中投入使用。

@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;

              }

问题是 getJpegCallback 方法不正确:(文件夹中没有日志和图像)ю 当我调试应用程序时,TAG - getJpegCallback不显示在 LogCat 中,但 TAG takePictureNoPreview 显示。关闭应用程序后,相机不允许(现在没问题)。怎么了?

4

6 回答 6

3

我在开发EyeSpy时遇到了这个问题。即使应用程序在背景或前景中,我也想捕捉图像。我尝试了几个星期,但没有运气。使用相机拍摄照片意味着显示其预览。

从 Document (5. and 6.) 你必须使用SurfaceView来显示预览。

当您关闭应用程序或您的应用程序进入后台时,表面SurfaceView将被破坏。这就是为什么我认为这是不可能的。

如果您发现任何其他方式,请在此处发布。

希望这对你有帮助..

于 2013-09-05T11:34:34.777 回答
2

从 API 11 开始,SurfaceHolderSurfaceView可以使用SurfaceTexture. 然后,您使用Camera.setPreviewTexture而不是Camera.setPreviewDisplay.

在不同设备上的服务中,它对我来说效果很好。

This answer以及this one讨论了这一点。

于 2014-06-16T07:29:03.150 回答
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 回答
0

不知道这是否为时已晚,但对于仍在搜索的任何人,请尝试使用此Android 背景摄像头 https://github.com/YoboZorle/Android-Background-Camera

于 2020-10-15T07:31:16.680 回答
0

似乎解决方案已经晚了,但仍然......实际上我们可以通过WindowManageronCreate() 中的 usgin 从服务中获得一个 UI 并膨胀一个布局......并且setVisibility(View.INVISIBLE)

@Override public void onCreate() {
        super.onCreate();
        windowManager = (WindowManager) getSystemService(WINDOW_SERVICE);
        inflater = (LayoutInflater) getSystemService(LAYOUT_INFLATER_SERVICE);
        recording = false;
        myview = inflater.inflate(R.layout.service_layout, null);
        layout = (FrameLayout) myview.findViewById(R.id.preview);
        minimize = (ImageButton) myview.findViewById(R.id.minimize);
        minimize.setVisibility(ImageButton.GONE);
        start = (Button) myview.findViewById(R.id.record);
        start.setVisibility(Button.GONE);
        start.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(!recording) {
                    if (prepareMediaRecorder()) {
                        try {
                            mediaRecorder.start();
                            Log.e("Camera------>", "working after");
                            recording = true;
                            start.setText("STOP");
                            handler.post(sendUpdates);
                        }catch (Exception e){
                            Log.getStackTraceString(e);
                        }
                    }
                }else{
                    mediaRecorder.stop(); // stop the recording
                    releaseMediaRecorder();
                    recording = false;
                    Log.e("Camera1------>", "working");
                    start.setText("START");
                    handler.post(sendUpdates);
                }

            }
        });

您还可以参考示例应用程序https://github.com/gauravbspr/Research-Projects/tree/master/Camera%20Service并在必要时提供帮助

于 2018-04-19T10:57:49.520 回答
-1

你可以试试这个

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" />

做这对我有用。希望能帮助到你。

于 2014-12-06T06:23:57.040 回答