如何在android zxing中扫描嵌入权重的条形码

在Android中使用ZXing库进行扫描嵌入权重的条形码可以按以下步骤进行：

首先，确保你的Android项目中已经集成了ZXing库。你可以通过将以下代码添加到项目的build.gradle文件中来添加ZXing依赖项：

implementation 'com.google.zxing:core:3.4.0'
implementation 'com.journeyapps:zxing-android-embedded:3.6.0'

创建一个用于扫描的Activity或Fragment，并在布局文件中添加一个用于扫描的视图。
在你的扫描Activity或Fragment的代码中，使用ZXing库提供的CaptureManager类来管理扫描过程。你可以在onCreate方法中初始化CaptureManager，并在onResume方法中启动扫描：

private CaptureManager captureManager;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    // 初始化CaptureManager
    captureManager = new CaptureManager(this, barcodeScannerView);

    // 设置自定义的条形码解码器，以处理嵌入权重的条形码
    captureManager.getBarcodeView().setDecoderFactory(new WeightedDecoderFactory());

    // 启动扫描
    captureManager.initializeFromIntent(getIntent(), savedInstanceState);
    captureManager.decode();
}

@Override
protected void onResume() {
    super.onResume();
    captureManager.onResume();
}

@Override
protected void onPause() {
    super.onPause();
    captureManager.onPause();
}

@Override
protected void onDestroy() {
    super.onDestroy();
    captureManager.onDestroy();
}

创建一个自定义的条形码解码器，用于处理嵌入权重的条形码。你可以继承DefaultDecoderFactory类并实现自定义的解码器。在解码器中，你可以使用ZXing提供的WeightedQRCodeReader类来处理嵌入权重的条形码：

import com.google.zxing.BarcodeFormat;
import com.google.zxing.DecodeHintType;
import com.google.zxing.MultiFormatReader;
import com.google.zxing.ReaderException;
import com.google.zxing.Result;
import com.google.zxing.client.android.DecodeFormatManager;
import com.google.zxing.client.android.DecodeHintManager;
import com.google.zxing.client.android.camera.PlanarYUVLuminanceSource;
import com.google.zxing.client.android.camera.open.CameraFacing;
import com.google.zxing.client.android.camera.open.OpenCamera;
import com.google.zxing.client.android.result.ResultHandler;
import com.journeyapps.barcodescanner.BarcodeCallback;
import com.journeyapps.barcodescanner.BarcodeResult;
import com.journeyapps.barcodescanner.DecodeForcer;
import com.journeyapps.barcodescanner.Decoder;
import com.journeyapps.barcodescanner.DecoderFactory;
import com.journeyapps.barcodescanner.DecodingOptions;
import com.journeyapps.barcodescanner.SourceData;
import com.journeyapps.barcodescanner.camera.CameraManager;
import com.journeyapps.barcodescanner.camera.PlanarYUVLuminanceSource;
import com.journeyapps.barcodescanner.camera.Size;

import java.util.ArrayList;
import java.util.Collection;
import java.util.EnumMap;
import java.util.EnumSet;
import java.util.List;
import java.util.Map;
import java.util.Set;

public class WeightedDecoderFactory extends DefaultDecoderFactory {

    public WeightedDecoderFactory() {
        super();
    }

    @Override
    protected Decoder createDecoder(Map<DecodeHintType, ?> baseHints) {
        MultiFormatReader reader = new MultiFormatReader();
        List<BarcodeFormat> formats = new ArrayList<>();
        formats.addAll(DecodeFormatManager.ONE_D_FORMATS);
        formats.addAll(DecodeFormatManager.QR_CODE_FORMATS);
        formats.addAll(DecodeFormatManager.DATA_MATRIX_FORMATS);
        reader.setHints(getHints(formats, baseHints));
        return new WeightedDecoder(reader);
    }

    private Map<DecodeHintType, ?> getHints(Collection<BarcodeFormat> formats, Map<DecodeHintType, ?> baseHints) {
        Map<DecodeHintType, Object> hints = new EnumMap<>(DecodeHintType.class);
        hints.putAll(baseHints);
        hints.put(DecodeHintType.POSSIBLE_FORMATS, formats);
        return hints;
    }

    private static class WeightedDecoder extends Decoder {
        private MultiFormatReader reader;

        public WeightedDecoder(MultiFormatReader reader) {
            super(reader);
            this.reader = reader;
        }

        @Override
        public Result decode(SourceData source) {
            Result weightedResult = null;
            Result normalResult = null;
            try {
                PlanarYUVLuminanceSource luminanceSource = cameraManager.buildLuminanceSource(source);
                BinaryBitmap bitmap = new BinaryBitmap(new HybridBinarizer(luminanceSource));

                WeightedQRCodeReader weightedReader = new WeightedQRCodeReader(reader);

                try {
                    weightedResult = weightedReader.decode(bitmap, hintManager.buildDecodeHints());
                } catch (NotFoundException e) {
                    // Continue decoding using normal QRCodeReader
                    normalResult = reader.decodeWithState(bitmap);
                } finally {
                    reader.reset();
                }
            } catch (Throwable t) {
                Log.e(TAG, "Unexpected error during decoding", t);
            }

            if (weightedResult != null) {
                return weightedResult;
            } else {
                return normalResult;
            }
        }
    }

    private static class WeightedQRCodeReader extends QRCodeReader {
        private final double weightThreshold = 0.8; // 嵌入权重的阈值

        public WeightedQRCodeReader(Reader delegate) {
            super(delegate);
        }

        @Override
        public Result decode(BinaryBitmap image, Map<DecodeHintType, ?> hints) throws NotFoundException, ChecksumException, FormatException {
            Result result = super.decode(image, hints);
            if (result != null && result instanceof WeightedResult) {
                WeightedResult weightedResult = (WeightedResult) result;
                if (weightedResult.getWeight() >= weightThreshold) {
                    return result;
                }
            }
            throw NotFoundException.getNotFoundInstance();
        }
    }
}