我在应用程序中使用google vision读取条形码和二维码。这很好用，但是当扫描的表面彼此相邻有2个代码时会崩溃，如下图所示。
即使对代码进行了单独扫描，即使对它们进行了正确扫描，也会发生这种情况。有谁知道如何阻止这种情况的发生？
以下是管理代码扫描 Activity 的代码:
public class ScanningActivity extends AppCompatActivity {
SurfaceView cameraPreview;
BarcodeDetector barcodeDetector;
CameraSource cameraSource;
final Integer requestCameraPermissionID = 1001;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.home_activity_add_scanner);
final int height = getSurfaceViewHeight();
final int width = getSurfaceViewWidth();
cameraPreview = findViewById(R.id.surfaceview_scanner);
barcodeDetector = new BarcodeDetector.Builder(AddScanningActivity.this)
.setBarcodeFormats(Barcode.ALL_FORMATS)
.build();
cameraSource = new CameraSource.Builder(AddScanningActivity.this, barcodeDetector)
.setAutoFocusEnabled(true)
.setRequestedPreviewSize(width, height)
.build();
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) {
Vibrator vibrator = (Vibrator) getApplicationContext().getSystemService(VIBRATOR_SERVICE);
vibrator.vibrate(100);
Handler handler = new Handler(Looper.getMainLooper());
handler.post(new Runnable() {
@Override
public void run() {
cameraSource.release();
}
});
}
}
});
cameraPreview.getHolder().addCallback(new SurfaceHolder.Callback() {
@Override
public void surfaceCreated(SurfaceHolder surfaceHolder) {
final Handler handler = new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
if (ActivityCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(AddScanningActivity.this,
new String[]{Manifest.permission.CAMERA}, requestCameraPermissionID);
return;
}
try {
cameraSource.start(cameraPreview.getHolder());
} catch (IOException e) {
e.printStackTrace();
}
}
}, 100);
}
@Override
public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) {
}
@Override
public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
cameraSource.stop();
}
});
}
private Integer getSurfaceViewHeight() {
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
Integer screenHeight = size.y;
Rect rectangle = new Rect();
Window window = getWindow();
window.getDecorView().getWindowVisibleDisplayFrame(rectangle);
final int statusBarHeight = rectangle.top;
int[] attrs = new int[]{R.attr.actionBarSize};
TypedArray ta = this.obtainStyledAttributes(attrs);
final int actionBarHeight = ta.getDimensionPixelSize(0, -1);
ta.recycle();
return screenHeight - statusBarHeight - actionBarHeight;
}
private Integer getSurfaceViewWidth() {
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
return size.x;
}
}
最佳答案
问题是在释放cameraSource之前，第二次调用了receiveDetections方法。然后第二次调用它，该方法尝试再次释放cameraSource，但是它不再可用，从而导致错误。下面是工作代码，只有一个小的简单更改，即使用 bool(boolean) 值“codeDetected”:
public class AddScanningActivity extends AppCompatActivity {
SurfaceView cameraPreview;
BarcodeDetector barcodeDetector;
CameraSource cameraSource;
final Integer requestCameraPermissionID = 1001;
Boolean codeDetected = false;
@Override
protected void onCreate(@Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.home_activity_add_scanner);
final int height = getSurfaceViewHeight();
final int width = getSurfaceViewWidth();
cameraPreview = findViewById(R.id.surfaceview_scanner);
barcodeDetector = new BarcodeDetector.Builder(AddScanningActivity.this)
.setBarcodeFormats(Barcode.ALL_FORMATS)
.build();
cameraSource = new CameraSource.Builder(AddScanningActivity.this, barcodeDetector)
.setAutoFocusEnabled(true)
.setRequestedPreviewSize(width, height)
.build();
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 && !codeDetected) {
codeDetected = true;
Vibrator vibrator = (Vibrator) getApplicationContext().getSystemService(VIBRATOR_SERVICE);
vibrator.vibrate(100);
Handler handler = new Handler(Looper.getMainLooper());
handler.post(new Runnable() {
@Override
public void run() {
cameraSource.release();
}
});
}
}
});
cameraPreview.getHolder().addCallback(new SurfaceHolder.Callback() {
@Override
public void surfaceCreated(SurfaceHolder surfaceHolder) {
final Handler handler = new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
if (ActivityCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(AddScanningActivity.this,
new String[]{Manifest.permission.CAMERA}, requestCameraPermissionID);
return;
}
try {
cameraSource.start(cameraPreview.getHolder());
} catch (IOException e) {
e.printStackTrace();
}
}
}, 100);
}
@Override
public void surfaceChanged(SurfaceHolder surfaceHolder, int i, int i1, int i2) {
}
@Override
public void surfaceDestroyed(SurfaceHolder surfaceHolder) {
cameraSource.stop();
}
});
}
private Integer getSurfaceViewHeight() {
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
Integer screenHeight = size.y;
Rect rectangle = new Rect();
Window window = getWindow();
window.getDecorView().getWindowVisibleDisplayFrame(rectangle);
final int statusBarHeight = rectangle.top;
int[] attrs = new int[] {R.attr.actionBarSize};
TypedArray ta = this.obtainStyledAttributes(attrs);
final int actionBarHeight = ta.getDimensionPixelSize(0, -1);
ta.recycle();
return screenHeight - statusBarHeight - actionBarHeight;
}
private Integer getSurfaceViewWidth() {
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
return size.x;
}
}
关于android - 出现2个代码时，Google Vision崩溃，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/48400312/