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Java 条形码扫描结果两次_Java_Android_Barcode_Barcode Scanner - Fatal编程技术网

Java 条形码扫描结果两次

Java 条形码扫描结果两次,java,android,barcode,barcode-scanner,Java,Android,Barcode,Barcode Scanner,你好,我试图开发一个应用程序,我应该能够扫描的主要活动和意图,我得到一个文本框的结果。我唯一的问题是,当我扫描条形码时,有时会打开结果活动2-3次。。也许有人能帮我我不知道该怎么办 我不知道该怎么帮你 @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main);

你好,我试图开发一个应用程序,我应该能够扫描的主要活动和意图,我得到一个文本框的结果。我唯一的问题是,当我扫描条形码时,有时会打开结果活动2-3次。。也许有人能帮我我不知道该怎么办

我不知道该怎么帮你

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

    if (ContextCompat.checkSelfPermission(this, Manifest.permission.INTERNET) != PackageManager.PERMISSION_GRANTED){
        ActivityCompat.requestPermissions(this, new  String[]{Manifest.permission.INTERNET}, 200);
    }


    if (ContextCompat.checkSelfPermission(this, android.Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED)
    {
        ActivityCompat.requestPermissions(this, new String[]{android.Manifest.permission.CAMERA}, 200);
    }


    cameraPreview = (SurfaceView) findViewById(R.id.cameraPreview);
    cameraPreview.setZOrderMediaOverlay(true);

    barcodeDetector = new BarcodeDetector.Builder(this)
            .setBarcodeFormats(Barcode.ALL_FORMATS)
            .build();
    cameraSource = new CameraSource
            .Builder(this, barcodeDetector)
            .setFacing(CameraSource.CAMERA_FACING_BACK)
            .setRequestedFps(24)
            .setRequestedPreviewSize(1600, 1024)
            .setAutoFocusEnabled(true)
            .build();
    cameraPreview.getHolder().addCallback(new SurfaceHolder.Callback() {
        @Override
        public void surfaceCreated(SurfaceHolder holder) {
            try{
                if(ContextCompat.checkSelfPermission(MainActivity.this, android.Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED){
                    cameraSource.start(cameraPreview.getHolder());
                }
            }
            catch (IOException e){
                e.printStackTrace();
            }
        }

        @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)
             {
                 Intent intent = new Intent(MainActivity.this, finish.class);
                 intent.putExtra("barcode", barcodes.valueAt(0));
                 startActivityForResult(intent, 100);
                 finish();

             }

             }

    });

}
@Override
protected void onDestroy() {
    super.onDestroy();
    cameraSource.release();
    barcodeDetector.release();
}

您可能不希望在onCreate中进行设置,而在onDestroy中进行拆卸。如果您这样做,即使您的活动已移到背景,相机仍将处于活动状态并进行扫描。改用onResume和onPause


您可能遇到的另一个问题是,
receiveDetections
每次检测到条形码时都会被调用(即使是相同的条形码)。如果条形码检测器检测条形码的速度快于系统启动活动的速度,则在释放摄像头和条形码检测器之前,将多次调用回调。为了防止这种情况发生,您可以使用一个标志来防止多次调用
startActivity
,或者您可以从内部
receiveDetections

释放条形码检测器,您可以在收到条形码数据后立即释放条形码检测器

 barcodeDetector.setProcessor(new Detector.Processor<Barcode>() {
        @Override
        public void release() {
        }

        @Override
        public void receiveDetections(Detector.Detections<Barcode> detections) {
            final SparseArray<Barcode> barcode = detections.getDetectedItems();
            if (barcode.size() != 0) {
                barcodeDetector.release();
                //......put your code here.....//
            }
        }
    });
barcodeDetector.setProcessor(新的Detector.Processor(){
@凌驾
公开无效释放(){
}
@凌驾
公共空隙接收检测(检测器。检测){
最终SparseArray条形码=检测。getDetectedItems();
如果(条形码大小()!=0){
条形码检测器。释放();
//……请将您的代码放在此处//
}
}
});

这看起来更像是一个编码问题,而不是关于条形码或扫描仪的问题。是的,你有权利,但没有人向我发送信息
 barcodeDetector.setProcessor(new Detector.Processor<Barcode>() {
        @Override
        public void release() {
        }

        @Override
        public void receiveDetections(Detector.Detections<Barcode> detections) {
            final SparseArray<Barcode> barcode = detections.getDetectedItems();
            if (barcode.size() != 0) {
                barcodeDetector.release();
                //......put your code here.....//
            }
        }
    });