Android之 Zxing二维码详解

一 简介

1.1 ZXing

目前Android扫描二维码，条形码主要用google官方的工具Zxing，支持扫码，相册解码，生成带logo的二维码等功能 

Zxing github 示例地址：https://github.com/zxing/zxing

1.2 ZBar

由于zxing是基于java编写的，扫码速度和解析上可能没那么快，但大部分场合足够用。也有基于c/c++的库zbar，需要编译通过才能用，下面是官网，有兴趣的可以编译试试：

ZBar官网：http://zbar.sourceforge.net/
ZBar GitHub地址：https://github.com/ZBar/ZBar

1.3  华为ScanKit

目前体验最好的华为统一扫码SDK，基本可以做到秒扫和快速识别，支持多码识别和二维码生成。但该服务必须在华为开发者联盟平台注册应用，配置包名和服务json

https://gitee.com/hms-core/hms-scan-demo华为官方demo示例 gitee地址：https://gitee.com/hms-core/hms-scan-demo

二 Zxing使用

2.1 依赖远程zxing库

dependencies {

  //zxing的core库
  implementation "com.google.zxing:core:3.5.1"
 
  //zxing
  implementation "com.google.zxing:zxing-parent:3.5.1"

  //zxing
  implementation 'com.journeyapps:zxing-android-embedded:4.1.0'

}

或直接使用下面库，目前识别比较快的Zxing库

implementation 'com.journeyapps:zxing-android-embedded:4.3.0'

2.2 添加权限

2.3 调用SDK的扫码页面并返回结果

/**
 * 跳转到扫码界面扫码
 */
private void goScan(){
    Intent intent = new Intent(MainActivity.this, CaptureActivity.class);
    startActivityForResult(intent, REQUEST_CODE_SCAN);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    // 扫描二维码/条码回传
    if (requestCode == REQUEST_CODE_SCAN && resultCode == RESULT_OK) {
        if (data != null) {
            //返回的文本内容
            String content = data.getStringExtra(DECODED_CONTENT_KEY);
            //返回的BitMap图像
            Bitmap bitmap = data.getParcelableExtra(DECODED_BITMAP_KEY);
        }
    }
}

三 自定义扫码页面

3.1 效果图

3.2 activity_scan.xml

3.3 ScanActivity.java

public class ScanActivity extends BaseActivity {
    private DecoratedBarcodeView decoratedBarcodeView;
   
    @Override
    protected int getLayoutId() {
        return R.layout.activity_scan;
    }

    @Override
    public void initData() {
        decoratedBarcodeView = new DecoratedBarcodeView(this);
        decoratedBarcodeView.setLayoutParams(new FrameLayout.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
        decoratedBarcodeView.setStatusText("");
        decoratedBarcodeView.getViewFinder().setVisibility(View.GONE);
        decoratedBarcodeView.getCameraSettings().setAutoFocusEnabled(true);
        mDataBinding.vScanLayout.removeAllViews();
        mDataBinding.vScanLayout.addView(decoratedBarcodeView);

        checkCameraPermission();
       
    }

    public final int REQUEST_CAMERA_PERMISSION = 1;
    private String cameraPermission = Manifest.permission.CAMERA;

    private void checkCameraPermission() {
        //检查是否有相机权限
        if (ContextCompat.checkSelfPermission(this, cameraPermission) != PackageManager.PERMISSION_GRANTED) {
            //没权限，请求权限
            ActivityCompat.requestPermissions(this, new String[]{cameraPermission},
                    REQUEST_CAMERA_PERMISSION);
        } else {
            //有权限
            scanLaunch();
        }
    }

    //权限请求回调
    @Override
    public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        switch (requestCode) {
            case REQUEST_CAMERA_PERMISSION:
                if (grantResults != null && grantResults.length > 0
                        && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                    //用户同意权限
                    scanLaunch();
                } else {
                    // 权限被用户拒绝了，可以提示用户,关闭界面等等。
                    Toast.makeText(this, "拒绝权限，请去设置里面手动开启权限", Toast.LENGTH_SHORT).show();
                }
                break;
        }
    }

    /**
     * 开始扫描
     */
    private void scanLaunch() {
        Collection formats = Arrays.asList(BarcodeFormat.QR_CODE, BarcodeFormat.CODE_39);
        decoratedBarcodeView.getBarcodeView().setDecoderFactory(new DefaultDecoderFactory(formats));
        decoratedBarcodeView.initializeFromIntent(getIntent());
        decoratedBarcodeView.decodeContinuous(callback);
        startScanAnimal();
    }

    private BarcodeCallback callback = new BarcodeCallback() {
        @Override
        public void barcodeResult(BarcodeResult result) {
            String originalValue = result.getText();
            if (TextUtils.isEmpty(originalValue)) {
                // Prevent duplicate scans
                return;
            }
            toResult(originalValue);
        }

        @Override
        public void possibleResultPoints(List resultPoints) {
        }
    };

    private void toResult(String originalValue) {
        Intent intent=new Intent(mContext,ScanResultActivity.class);
        intent.putExtra("result",originalValue);
        startActivity(intent);
    }

    @Override
    protected void onResume() {
        super.onResume();
        decoratedBarcodeView.resume();


    }

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

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (animation != null) {
            animation.cancel();
        }
    }

    //扫码线动画
    private Animation animation;

    private void startScanAnimal() {
        animation = new TranslateAnimation(0, 0, 0, StatuesBarUtils.getScreenWidth(this) - StatuesBarUtils.dp2px(this, 100));
        animation.setDuration(2000);
        animation.setRepeatCount(Animation.INFINITE);//动画的反复次数
        animation.setFillAfter(true);//设置为true，动画转化结束后被应用
        //animation.setRepeatMode(ObjectAnimator.RESTART);//重复模式
        animation.setInterpolator(new LinearInterpolator());
        mDataBinding.scanLine.startAnimation(animation);//開始动画
    }
}

四 相册选区图片解析二维码

4.1 选择相册图片

private void setPictureScanOperation() {
        imgBtn = findViewById(R.id.img_btn);
        imgBtn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
               Intent pickIntent = new Intent(Intent.ACTION_PICK,
                        MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
                pickIntent.setDataAndType(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, "image/*");
               ZxingActivity.this.startActivityForResult(pickIntent, REQUEST_CODE_PHOTO);
            }
        });
    }

4.2 本地图片文件转换成可解码二维码的 Bitmap

/**
     * 将本地图片文件转换成可解码二维码的 Bitmap。为了避免图片太大，这里对图片进行了压缩。
     *
     * @param picturePath 本地图片文件路径
     */
    public static Bitmap getDecodeAbleBitmap(String picturePath) {
        try {
            BitmapFactory.Options options = new BitmapFactory.Options();
            options.inJustDecodeBounds = true;
            BitmapFactory.decodeFile(picturePath, options);
            int sampleSize = options.outHeight / 400;
            if (sampleSize <= 0) {
                sampleSize = 1;
            }
            options.inSampleSize = sampleSize;
            options.inJustDecodeBounds = false;

            return BitmapFactory.decodeFile(picturePath, options);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

4.3  解析二维码图片

 /**
     * 同步解析bitmap二维码。该方法是耗时操作，请在子线程中调用。
     *
     * @param bitmap 要解析的二维码图片
     * @return 返回二维码图片里的内容 或 null
     */
    public static String syncDecodeQRCode(Bitmap bitmap) {
        Result result;
        RGBLuminanceSource source = null;
        try {
            int width = bitmap.getWidth();
            int height = bitmap.getHeight();
            int[] pixels = new int[width * height];
            bitmap.getPixels(pixels, 0, width, 0, 0, width, height);
            source = new RGBLuminanceSource(width, height, pixels);
            result = new MultiFormatReader().decode(new BinaryBitmap(new HybridBinarizer(source)), new EnumMap<>(DecodeHintType.class));
            return result.getText();
        } catch (Exception e) {
            e.printStackTrace();
            if (source != null) {
                try {
                    result = new MultiFormatReader().decode(new BinaryBitmap(new GlobalHistogramBinarizer(source)), new EnumMap<>(DecodeHintType.class));
                    return result.getText();
                } catch (Throwable e2) {
                    e2.printStackTrace();
                }
            }
            return null;
        }
    }

五 生成二维码

5.1 效果图，支持修改边框颜色大小，二维码颜色大小，背景颜色，logo样式和圆角

5.2 activity_qrcode_style_xml

 5.3 核心生成二维码源码，QRCodeEncoder.java

public class QRCodeEncoder {
    public static final Map HINTS = new EnumMap<>(EncodeHintType.class);

    static {
        HINTS.put(EncodeHintType.CHARACTER_SET, "utf-8");
        HINTS.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
        HINTS.put(EncodeHintType.MARGIN, 0);
    }

    private QRCodeEncoder() {
    }

    /**
     * 同步创建黑色前景色、白色背景色的二维码图片。该方法是耗时操作，请在子线程中调用。
     *
     * @param content 要生成的二维码图片内容
     * @param size    图片宽高，单位为px
     */
    public static Bitmap syncEncodeQRCode(String content, int size) {
        return syncEncodeQRCode(content, size, Color.BLACK, Color.WHITE, null);
    }

    /**
     * 同步创建指定前景色、白色背景色的二维码图片。该方法是耗时操作，请在子线程中调用。
     *
     * @param content         要生成的二维码图片内容
     * @param size            图片宽高，单位为px
     * @param foregroundColor 二维码图片的前景色
     */
    public static Bitmap syncEncodeQRCode(String content, int size, int foregroundColor) {
        return syncEncodeQRCode(content, size, foregroundColor, Color.WHITE, null);
    }

    /**
     * 同步创建指定前景色、白色背景色、带logo的二维码图片。该方法是耗时操作，请在子线程中调用。
     *
     * @param content         要生成的二维码图片内容
     * @param size            图片宽高，单位为px
     * @param foregroundColor 二维码图片的前景色
     * @param logo            二维码图片的logo
     */
    public static Bitmap syncEncodeQRCode(String content, int size, int foregroundColor, Bitmap logo) {
        return syncEncodeQRCode(content, size, foregroundColor, Color.WHITE, logo);
    }

    /**
     * 同步创建指定前景色、指定背景色、带logo的二维码图片。该方法是耗时操作，请在子线程中调用。
     *
     * @param content         要生成的二维码图片内容
     * @param size            图片宽高，单位为px
     * @param foregroundColor 二维码图片的前景色
     * @param backgroundColor 二维码图片的背景色
     * @param logo            二维码图片的logo
     */
    public static Bitmap syncEncodeQRCode(String content, int size, int foregroundColor, int backgroundColor, Bitmap logo) {
        try {
            BitMatrix matrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, size, size, HINTS);
            int[] pixels = new int[size * size];
            for (int y = 0; y < size; y++) {
                for (int x = 0; x < size; x++) {
                    if (matrix.get(x, y)) {
                        pixels[y * size + x] = foregroundColor;
                    } else {
                        pixels[y * size + x] = backgroundColor;
                    }
                }
            }
            Bitmap bitmap = Bitmap.createBitmap(size, size, Bitmap.Config.ARGB_8888);
            bitmap.setPixels(pixels, 0, size, 0, 0, size, size);
            return addLogoToQRCode(bitmap, logo);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    /**
     * 同步创建指定前景色、指定背景色、带logo的二维码图片。该方法是耗时操作，请在子线程中调用。
     *
     * @param content         要生成的二维码图片内容
     * @param size            图片宽高，单位为px
     * @param foregroundColor 二维码图片的前景色
     * @param backgroundColor 二维码图片的背景色
     * @param logo            二维码图片的logo
     * @param borderColor     边框颜色
     */
    public static Bitmap syncEncodeQRCode(String content, int size, int foregroundColor, int backgroundColor, Bitmap logo ,int border , int borderColor) {
        int borderWidth= (int) dp2px(MyApp.getInstance(),4);
        size-=borderWidth*2;
        try {
            BitMatrix matrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, size, size, HINTS);
            int[] pixels = new int[size * size];
            for (int y = 0; y < size; y++) {
                for (int x = 0; x < size; x++) {
                    if (matrix.get(x, y)) {
                        pixels[y * size + x] = foregroundColor;
                    } else {
                        pixels[y * size + x] = backgroundColor;
                    }
                }
            }
            Bitmap bitmap = Bitmap.createBitmap(size, size, Bitmap.Config.ARGB_8888);
            bitmap.setPixels(pixels, 0, size, 0, 0, size, size);
            if(bitmap!=null){
                bitmap=addLogoToQRCode(bitmap, logo);
            }

            bitmap=addBorderToQRCode(bitmap,backgroundColor ,border,borderColor);

            return bitmap;
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }
    /**
     * 添加logo到二维码图片上
     */
    private static Bitmap addBorderToQRCode(Bitmap src, int backgroundColor, int border , int borderColor) {
        if (src == null) {
            return src;
        }

        if(borderColor==0){
            borderColor=Color.parseColor("#63C99B");
        }

        int srcWidth = src.getWidth();
        int srcHeight = src.getHeight();


        int borderWidth= (int) dp2px(MyApp.getInstance(),4);
        Bitmap bitmap = Bitmap.createBitmap(srcWidth+borderWidth, srcHeight+borderWidth, Bitmap.Config.ARGB_8888);
        try {
            Canvas canvas = new Canvas(bitmap);
            canvas.drawColor(backgroundColor);
            if(border!=0){
                Paint paintRect = new Paint();
                paintRect.setColor(borderColor);
                paintRect.setStrokeWidth(borderWidth);
                if(border==1){
                    paintRect.setPathEffect(new DashPathEffect(new float[]{8, 8}, 0)); // 设置虚线样式
                }
                paintRect.setStyle(Paint.Style.STROKE);
                canvas.drawRect(0, 0, bitmap.getWidth(), bitmap.getHeight(), paintRect);
            }
            canvas.drawBitmap(src, borderWidth/2f, borderWidth/2f, null);

            canvas.save();
            canvas.restore();
        } catch (Exception e) {
            e.printStackTrace();
            bitmap = null;
        }
        return bitmap;
    }


    /**
     * 添加logo到二维码图片上
     */
    private static Bitmap addLogoToQRCode(Bitmap src, Bitmap logo) {
        if (src == null || logo == null) {
            return src;
        }

        int srcWidth = src.getWidth();
        int srcHeight = src.getHeight();
        int logoWidth = logo.getWidth();
        int logoHeight = logo.getHeight();

        float scaleFactor = srcWidth * 1.0f / 5 / logoWidth;
        Bitmap bitmap = Bitmap.createBitmap(srcWidth, srcHeight, Bitmap.Config.ARGB_8888);
        try {
            Canvas canvas = new Canvas(bitmap);
            canvas.drawBitmap(src, 0, 0, null);
            canvas.scale(scaleFactor, scaleFactor, srcWidth / 2, srcHeight / 2);
            canvas.drawBitmap(logo, (srcWidth - logoWidth) / 2, (srcHeight - logoHeight) / 2, null);
            canvas.save();
            canvas.restore();
        } catch (Exception e) {
            e.printStackTrace();
            bitmap = null;
        }
        return bitmap;
    }

    /**
     * 同步创建条形码图片
     *
     * @param content  要生成条形码包含的内容
     * @param width    条形码的宽度，单位px
     * @param height   条形码的高度，单位px
     * @param textSize 字体大小，单位px，如果等于0则不在底部绘制文字
     * @return 返回生成条形的位图
     */
    public static Bitmap syncEncodeBarcode(String content, int width, int height, int textSize) {
        if (TextUtils.isEmpty(content)) {
            return null;
        }
        Map hints = new HashMap<>();
        hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
        hints.put(EncodeHintType.MARGIN, 0);

        try {
            BitMatrix bitMatrix = new MultiFormatWriter().encode(content, BarcodeFormat.CODE_128, width, height, hints);
            int[] pixels = new int[width * height];
            for (int y = 0; y < height; y++) {
                for (int x = 0; x < width; x++) {
                    if (bitMatrix.get(x, y)) {
                        pixels[y * width + x] = 0xff000000;
                    } else {
                        pixels[y * width + x] = 0xffffffff;
                    }
                }
            }
            Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
            bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
            if (textSize > 0) {
                bitmap = showContent(bitmap, content, textSize);
            }
            return bitmap;
        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }

    /**
     * 显示条形的内容
     *
     * @param barcodeBitmap 已生成的条形码的位图
     * @param content       条形码包含的内容
     * @param textSize      字体大小，单位px
     * @return 返回生成的新条形码位图
     */
    private static Bitmap showContent(Bitmap barcodeBitmap, String content, int textSize) {
        if (TextUtils.isEmpty(content) || null == barcodeBitmap) {
            return null;
        }
        Paint paint = new Paint();
        paint.setColor(Color.BLACK);
        paint.setAntiAlias(true);
        paint.setStyle(Paint.Style.FILL);
        paint.setTextSize(textSize);
        paint.setTextAlign(Paint.Align.CENTER);
        int textWidth = (int) paint.measureText(content);
        Paint.FontMetrics fm = paint.getFontMetrics();
        int textHeight = (int) (fm.bottom - fm.top);
        float scaleRateX = barcodeBitmap.getWidth() * 1.0f / textWidth;
        if (scaleRateX < 1) {
            paint.setTextScaleX(scaleRateX);
        }
        int baseLine = barcodeBitmap.getHeight() + textHeight;
        Bitmap bitmap = Bitmap.createBitmap(barcodeBitmap.getWidth(), barcodeBitmap.getHeight() + 2 * textHeight, Bitmap.Config.ARGB_4444);
        Canvas canvas = new Canvas();
        canvas.drawColor(Color.WHITE);
        canvas.setBitmap(bitmap);
        canvas.drawBitmap(barcodeBitmap, 0, 0, null);
        canvas.drawText(content, barcodeBitmap.getWidth() / 2, baseLine, paint);
        canvas.save();
        canvas.restore();
        return bitmap;
    }

    public static float dp2px(Context context, float dpValue) {
        final float scale = context.getResources().getDisplayMetrics().density;
        return dpValue * scale + 0.5f;
    }
}

5.4 异步调用QRCodeEncoder生成二维码

 private void updateQrcode(){
        new GenerateQrcodeTask().execute(content);
    }

    public class GenerateQrcodeTask extends AsyncTask {

        @Override
        protected Bitmap doInBackground(String... strings) {
            Bitmap logoBitmap=null;
            if(logo!=0){
                logoBitmap = BitmapFactory.decodeResource(getResources(), logo);
            }

            int borderColor22=TextUtils.isEmpty(borderColor)?0:Color.parseColor(borderColor);
            return QRCodeEncoder.syncEncodeQRCode(strings[0], (int) StatuesBarUtils.dp2px(mContext, 300f), Color.parseColor(qianColor),Color.parseColor(beinColor),logoBitmap, border , borderColor22);

        }

        @Override
        protected void onPostExecute(Bitmap bitmap) {
            super.onPostExecute(bitmap);
            qrBitmap=bitmap;
            if (bitmap != null) {
                mDataBinding.vImage.setImageBitmap(qrBitmap);
            } else {
                Toast.makeText(mContext, "生成維碼失敗", Toast.LENGTH_SHORT).show();
            }
        }
    }

5.5 保存二维码，FileUtil.java工具类

public class FileUtil {

    public static String saveToImage(Bitmap bitmap) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
            return MediaStore.Images.Media.insertImage(MyApp.getInstance().getContentResolver(), bitmap, "", "");
        } else {

            try {

                File dir = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + File.separator + "qrcode");
                if (!dir.exists()) {
                    dir.mkdirs();
                }
                File picFile = new File(dir, System.currentTimeMillis() + ".png");
                FileOutputStream fos = new FileOutputStream(picFile);
                bitmap.compress(Bitmap.CompressFormat.PNG, 100, fos);
                fos.flush();
                fos.close();
                return picFile.getAbsolutePath();

            } catch (Exception e) {
                e.printStackTrace();
            }

        }
        return null;
    }

 异步调用FileUtil，保存二维码

public class SaveBitmapTask extends AsyncTask {


        @Override
        protected String doInBackground(Bitmap... bitmaps) {
            return FileUtil.saveToImage(bitmaps[0]);
        }

        @Override
        protected void onPostExecute(String result) {
            super.onPostExecute(result);
            if (result != null) {
                Intent intent = new Intent(mContext, QrBarcodeEditResultActivity.class);
                intent.putExtra("filePath", result);
                startActivity(intent);
            } else {
                Toast.makeText(mContext, "保存二維碼失敗", Toast.LENGTH_SHORT).show();
            }
        }
    }

5.6 核心源码解析，我们知道bitmap是一个保存所有像素内容的容器，那二维码原理即是把内容解析到每一个像素里面。如下

  /**
 *
 * @param content         要生成的二维码图片内容
 * @param size            图片宽高，单位为px
 * @param foregroundColor 二维码图片的前景色
 * @param backgroundColor 二维码图片的背景色
 * @param logo            二维码图片的logo
 * @param borderColor     边框颜色
 */
public static Bitmap syncEncodeQRCode(String content, int size, int foregroundColor, int backgroundColor, Bitmap logo ,int border , int borderColor) {
	int borderWidth= (int) dp2px(MyApp.getInstance(),4);
	size-=borderWidth*2;
	try {
		//内容解析到字节矩阵
		BitMatrix matrix = new MultiFormatWriter().encode(content, BarcodeFormat.QR_CODE, size, size, HINTS);
		//设置宽高像素数组
		int[] pixels = new int[size * size];
		//遍历记录图片每个像素信息
		for (int y = 0; y < size; y++) {
			for (int x = 0; x < size; x++) {
				if (matrix.get(x, y)) {
					pixels[y * size + x] = foregroundColor;
				} else {
					pixels[y * size + x] = backgroundColor;
				}
			}
		}
		//创建bitmap,设置像素数组
		Bitmap bitmap = Bitmap.createBitmap(size, size, Bitmap.Config.ARGB_8888);
		bitmap.setPixels(pixels, 0, size, 0, 0, size, size);
		if(bitmap!=null){
			bitmap=addLogoToQRCode(bitmap, logo);
		}

		//添加logo
		bitmap=addBorderToQRCode(bitmap,backgroundColor ,border,borderColor);

		return bitmap;
	} catch (Exception e) {
		e.printStackTrace();
		return null;
	}
}