我想在同一活动中停止相机源后重新启动相机源

Question

我为条形码检测器做了一个应用程序，所以我使用SurfaceView来处理相机源。相机检测到条形码并返回其值后，我使其停止。没有功能可以在任何事件上重新启动相机源和表面视图，只有一个功能是camersource.start((;

它开始了，但它在后台工作的问题，我看不到任何如何解决这个问题的方法？ 并再次显示表面视图和相机源。

这是创建方法上活动的完整代码

 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        surfaceView = (SurfaceView) findViewById(R.id.cameraPreview);
        txtShow = (TextView) findViewById(R.id.txtShow);
        startBarcode();
    }
    public void startBarcode() {
        barcodeDetector = new BarcodeDetector.Builder(this)
                .setBarcodeFormats(Barcode.ALL_FORMATS)
                .build();
        cameraSource = new CameraSource.Builder(this, barcodeDetector)
                .setRequestedPreviewSize(800, 600)
                .setAutoFocusEnabled(true)
                .build();
        //Events
        surfaceView.getHolder().addCallback(new SurfaceHolder.Callback() {
            @Override
            public void surfaceCreated(SurfaceHolder holder) {
                if (ActivityCompat.checkSelfPermission(getApplicationContext(), android.Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
                    //Make Request Runtime Permission
                    ActivityCompat.requestPermissions(MainActivity.this,
                            new String[]{Manifest.permission.CAMERA}, RequestCameraPermissionId);
                    return;
                }
                try {
                    cameraSource.start(surfaceView.getHolder());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            @Override
            public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
                if (ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
                    //Make Request Runtime Permission
                    ActivityCompat.requestPermissions(MainActivity.this,
                            new String[]{Manifest.permission.CAMERA}, RequestCameraPermissionId);
                    return;
                }
                try {
                    cameraSource.start();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            @Override
            public void surfaceDestroyed(SurfaceHolder holder) {
                cameraSource.stop();
            }
        });
        barcodeDetector.setProcessor(new Detector.Processor<Barcode>() {
            @Override
            public void release() {
            }
            @Override
            public void receiveDetections(Detector.Detections<Barcode> detections) {
                final SparseArray<Barcode> qrCodes = detections.getDetectedItems();
                if (qrCodes.size() != 0) {
                    txtShow.post(new Runnable() {
                        @Override
                        public void run() {
                            //create vibrate
                            Vibrator vibrator = (Vibrator) getApplicationContext().getSystemService(Context.VIBRATOR_SERVICE);
                            vibrator.vibrate(500);

                            //set result for Text View
                            txtShow.setText(qrCodes.valueAt(0).displayValue);
                            // surfaceView.setTop(200);
                            cameraSource.stop();

                            final MediaPlayer mp = MediaPlayer.create(MainActivity.this, R.raw.barcode);
                            mp.start();

Answer 1

要在 cameraSource.stop(( 之后重新启动，您需要：

cameraSource.start(surfaceView.getHolder());

Answer 2

捕获代码后，您可以停止相机源并再次重新启动 OnCreate 方法。 或者，您可以使用 Intent 再次调用该活动，如下所示：

Intent intent= new Intent (getBaseContext,MainActivity.class); // your activity
startActivity(intent);