Android API 用于打开相机和扫描二维码？

Question

我正在尝试开发一个可以打开相机并扫描给定二维码的应用程序。但是，我有一个限制，即我不能使用任何 3rd 方库，如 ZBar Code Reader 或 ZXingScanner，因为它会增加我的 apk 的大小。

我正在研究 here 给出的 Google Barcode APIs，但它似乎没有执行我希望我的应用程序执行的操作，也就是说，它不会打开任何相机并对图像进行实时扫描。

那么，如何让我的应用程序在特定范围内打开相机并对二维码进行实时扫描？

感谢您的宝贵时间！

Answer 1

Google条形码API提供打开相机的支持。这是示例代码

    // A barcode detector is created to track barcodes.  An associated multi-processor instance
    // is set to receive the barcode detection results, track the barcodes, and maintain
    // graphics for each barcode on screen.  The factory is used by the multi-processor to
    // create a separate tracker instance for each barcode.
    BarcodeDetector barcodeDetector = new BarcodeDetector.Builder(context).build();
    BarcodeTrackerFactory barcodeFactory = new BarcodeTrackerFactory(mGraphicOverlay);
    barcodeDetector.setProcessor(
            new MultiProcessor.Builder<>(barcodeFactory).build());

    if (!barcodeDetector.isOperational()) {
        // Note: The first time that an app using the barcode or face API is installed on a
        // device, GMS will download a native libraries to the device in order to do detection.
        // Usually this completes before the app is run for the first time.  But if that
        // download has not yet completed, then the above call will not detect any barcodes
        // and/or faces.
        //
        // isOperational() can be used to check if the required native libraries are currently
        // available.  The detectors will automatically become operational once the library
        // downloads complete on device.
        Log.w(TAG, "Detector dependencies are not yet available.");

        // Check for low storage.  If there is low storage, the native library will not be
        // downloaded, so detection will not become operational.
        IntentFilter lowstorageFilter = new IntentFilter(Intent.ACTION_DEVICE_STORAGE_LOW);
        boolean hasLowStorage = registerReceiver(null, lowstorageFilter) != null;

        if (hasLowStorage) {
            Toast.makeText(this, R.string.low_storage_error, Toast.LENGTH_LONG).show();
            Log.w(TAG, getString(R.string.low_storage_error));
        }
    }

    // Creates and starts the camera.  Note that this uses a higher resolution in comparison
    // to other detection examples to enable the barcode detector to detect small barcodes
    // at long distances.
    CameraSource.Builder builder = new CameraSource.Builder(getApplicationContext(), barcodeDetector)
            .setFacing(CameraSource.CAMERA_FACING_BACK)
            .setRequestedPreviewSize(1600, 1024)
            .setRequestedFps(15.0f);

    // make sure that auto focus is an available option
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
        builder = builder.setFocusMode(
                autoFocus ? Camera.Parameters.FOCUS_MODE_CONTINUOUS_PICTURE : null);
    }

    mCameraSource = builder
            .setFlashMode(useFlash ? Camera.Parameters.FLASH_MODE_TORCH : null)
            .build();
}

您可以在这里参考谷歌条形码示例

https://github.com/googlesamples/android-vision/tree/master/visionSamples/barcode-reader