使用相机扫描二维码应用程序崩溃 |可能的修复？

Question

我正在尝试使用设备相机和移动视觉 API 扫描二维码。为此，我创建了一个 SurfaceView 并将图像流提取到 SurfaceView 并启用了一个 BarcodeDetector，然后是读取检测到的二维码所需的方法。这是 Activity:

的代码

QrScanActivity.class

public class QrScanActivity extends AppCompatActivity
{
    private SurfaceView cameraView;
    private TextView barcodeInfo;
    private BarcodeDetector barcodeDetector;
    private CameraSource cameraSource;
    private static final String TAG = "QR_ACTIVITY";
    private static final int REQUEST_CAMERA = 0;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_qr_scan);

        cameraView = (SurfaceView) findViewById(R.id.camera_view);
        barcodeInfo = (TextView) findViewById(R.id.code_info);

        barcodeDetector =
                new BarcodeDetector.Builder(this)
                        .setBarcodeFormats(Barcode.QR_CODE)
                        .build();

        cameraSource = new CameraSource
                .Builder(this, barcodeDetector)
                .setRequestedPreviewSize(640, 480)
                .build();

        cameraView.getHolder().addCallback(new SurfaceHolder.Callback() {
            @Override
            public void surfaceCreated(SurfaceHolder holder) {
                if (ActivityCompat.checkSelfPermission(QrScanActivity.this, Manifest.permission.CAMERA)
                        != PackageManager.PERMISSION_GRANTED) {
                    requestCameraPermission();

                }
                try {
                    cameraSource.start(cameraView.getHolder());
                } catch (IOException ie) {
                    Log.e("CAMERA SOURCE", ie.getMessage());
                }
            }

            @Override
            public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
            }

            @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> barcodes = detections.getDetectedItems();

                if (barcodes.size() != 0) {
                    barcodeInfo.post(new Runnable() {    // Use the post method of the TextView
                        public void run() {
                            barcodeInfo.setText(    // Update the TextView
                                    barcodes.valueAt(0).displayValue
                            );
                        }
                    });
                }
            }
        });
    }

        private void requestCameraPermission() {
        Log.i("CAM","CAMERA permission has NOT been granted. Requesting permission.");

        // BEGIN_INCLUDE(camera_permission_request)
        if (ActivityCompat.shouldShowRequestPermissionRationale(this,Manifest.permission.CAMERA))
        {

            Snackbar.make(findViewById(android.R.id.content), R.string.permission_camera_rationale,
                    Snackbar.LENGTH_INDEFINITE)
                    .setAction(R.string.ok, new View.OnClickListener() {
                        @Override
                        public void onClick(View view) {
                            ActivityCompat.requestPermissions(QrScanActivity.this,
                                    new String[]{Manifest.permission.CAMERA},
                                    REQUEST_CAMERA);
                        }
                    })
                    .show();
        } else {


            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.CAMERA},
                    REQUEST_CAMERA);
        }
        // END_INCLUDE(camera_permission_request)
    }


    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,
                                           @NonNull int[] grantResults) {

        if (requestCode == REQUEST_CAMERA)
        {

            Log.i(TAG, "Received response for Camera permission request.");
           if (grantResults.length == 1 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                  Log.i(TAG, "CAMERA permission has now been granted. Showing preview.");
                Snackbar.make(findViewById(android.R.id.content), R.string.permision_available_camera,
                        Snackbar.LENGTH_SHORT).show();
            } else {
                Log.i(TAG, "CAMERA permission was NOT granted.");
                Snackbar.make(findViewById(android.R.id.content), R.string.permissions_not_granted,
                        Snackbar.LENGTH_SHORT).show();

            }


        }
        else {
            super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        }
    }




}

activity_qr_scan.xml

    <?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/activity_qr_scan"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <SurfaceView
        android:layout_width="400dp"
        android:layout_height="280dp"
        android:layout_marginTop="30dp"
        android:id="@+id/camera_view"
        />

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/code_info"
        android:layout_below="@+id/camera_view"
        android:textSize="20sp"
        android:layout_marginTop="30dp"
        android:layout_centerHorizontal="true"
        android:text="Nothing to read."

        />


</RelativeLayout>

app为运行时得到的logcat:

Logcat

E/AndroidRuntime: FATAL EXCEPTION: main Process: com.shreybank.shrey, PID: 12044 java.lang.RuntimeException: Fail to connect to camera service at android.hardware.Camera.(Camera.java:518) at android.hardware.Camera.open(Camera.java:360) at com.google.android.gms.vision.CameraSource.zzBZ(Unknown Source) at com.google.android.gms.vision.CameraSource.start(Unknown Source) at com.shreybank.shrey.activities.QrScanActivity.surfaceCreated(QrScanActivity.java:64) at android.view.SurfaceView.updateWindow(SurfaceView.java:583) at android.view.SurfaceView.onPreDraw(SurfaceView.java:177) at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:944) at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:2055) at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1107) at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6013) at android.view.Choreographer$CallbackRecord.run(Choreographer.java:858) at android.view.Choreographer.doCallbacks(Choreographer.java:670) at android.view.Choreographer.doFrame(Choreographer.java:606) at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:844) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:148) at android.app.ActivityThread.main(ActivityThread.java:5466) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

Answer 1

您必须设置运行时间权限才能解决此问题。在开始 QrScanActivity 之前你已经调用了这个。

if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
    if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.CAMERA}, REQUEST_READ_CAMERA);
    }
    else {
        // Already grant Camera permission. Now call your QR scan Activity
    }
}else {
    // call your QR scan Activity
}

当用户授予权限后，您可以打开 QrScanActivity onRequestPermissionsResult 方法。

@Override
public void onRequestPermissionsResult(int requestCode,
                                       String permissions[], int[] grantResults) {
    switch (requestCode) {
        case REQUEST_READ_CAMERA: {
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                // permission has granted . Call the QR scan Activity
            } else {
                // permission denied
            }
            return;
        }
    }
}

Answer 2

更新您的 QrScanActivity，将您的相机源代码创建代码移至 initCameraSource 方法，检查 CAMERA 的权限，如果获得授权则调用 initCameraSource 方法，否则请求权限。授予权限后，从 onRequestPermissionsResult 调用 initCameraSource。

public class QrScanActivity extends AppCompatActivity
{
    private SurfaceView cameraView;
    private TextView barcodeInfo;
    private BarcodeDetector barcodeDetector;
    private CameraSource cameraSource;
    private static final String TAG = "QR_ACTIVITY";
    private static final int REQUEST_CAMERA = 0;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_qr_scan);
        int permissionCheck = ContextCompat.checkSelfPermission(this,
                Manifest.permission.CAMERA);
        if(permissionCheck ==  PackageManager.PERMISSION_GRANTED)
            initCameraSource
        else
            requestCameraPermission();

    }

        private void requestCameraPermission() {
        Log.i("CAM","CAMERA permission has NOT been granted. Requesting permission.");

        // BEGIN_INCLUDE(camera_permission_request)
        if (ActivityCompat.shouldShowRequestPermissionRationale(this,Manifest.permission.CAMERA))
        {

            Snackbar.make(findViewById(android.R.id.content), R.string.permission_camera_rationale,
                    Snackbar.LENGTH_INDEFINITE)
                    .setAction(R.string.ok, new View.OnClickListener() {
                        @Override
                        public void onClick(View view) {
                            ActivityCompat.requestPermissions(QrScanActivity.this,
                                    new String[]{Manifest.permission.CAMERA},
                                    REQUEST_CAMERA);
                        }
                    })
                    .show();
        } else {


            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.CAMERA},
                    REQUEST_CAMERA);
        }
        // END_INCLUDE(camera_permission_request)
    }


    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions,
                                           @NonNull int[] grantResults) {

        if (requestCode == REQUEST_CAMERA)
        {

            Log.i(TAG, "Received response for Camera permission request.");
           if (grantResults.length == 1 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                  Log.i(TAG, "CAMERA permission has now been granted. Showing preview.");
                  initCameraSource();
            } else {
                Log.i(TAG, "CAMERA permission was NOT granted.");
                Snackbar.make(findViewById(android.R.id.content), R.string.permissions_not_granted,
                        Snackbar.LENGTH_SHORT).show();

            }


        }
        else {
            super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        }
    }


    private void initCameraSource(){
         cameraView = (SurfaceView) findViewById(R.id.camera_view);
         barcodeInfo = (TextView) findViewById(R.id.code_info);

         barcodeDetector =
                 new BarcodeDetector.Builder(this)
                         .setBarcodeFormats(Barcode.QR_CODE)
                         .build();

         cameraSource = new CameraSource
                 .Builder(this, barcodeDetector)
                 .setRequestedPreviewSize(640, 480)
                 .build();

         cameraView.getHolder().addCallback(new SurfaceHolder.Callback() {
             @Override
             public void surfaceCreated(SurfaceHolder holder) {
                 if (ActivityCompat.checkSelfPermission(QrScanActivity.this, Manifest.permission.CAMERA)
                         != PackageManager.PERMISSION_GRANTED) {
                     requestCameraPermission();

                 }
                 try {
                     cameraSource.start(cameraView.getHolder());
                 } catch (IOException ie) {
                     Log.e("CAMERA SOURCE", ie.getMessage());
                 }
             }

             @Override
             public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
             }

             @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> barcodes = detections.getDetectedItems();

                 if (barcodes.size() != 0) {
                     barcodeInfo.post(new Runnable() {    // Use the post method of the TextView
                         public void run() {
                             barcodeInfo.setText(    // Update the TextView
                                     barcodes.valueAt(0).displayValue
                             );
                         }
                     });
                 }
             }
         });
    }


}

使用相机扫描二维码应用程序崩溃 |可能的修复？

Scanning QR code using camera crashes application | possible fix?

java

camera

android