Android项目实战（五十四）：zxing 生成二维码图片去除白色内边距的解决方案

目录：zxing->encoding->EncodingHandler类 中修改 createQRCode方法

　　 private static final int BLACK = 0xff000000;
    private static final int WHITE = 0xffffffff;

    public static Bitmap createQRCode(String str,int widthAndHeight) throws WriterException {
        String contentsToEncode = str;
        if (contentsToEncode == null) {
            return null;
        }
        Map hints = new EnumMap<>(EncodeHintType.class);
        //hints.put(EncodeHintType.CHARACTER_SET, encoding);
        hints.put(EncodeHintType.MARGIN, 0); /* default = 4 */
        MultiFormatWriter writer = new MultiFormatWriter();
        BitMatrix result;
        try {
            result = writer.encode(contentsToEncode, BarcodeFormat.QR_CODE , widthAndHeight, widthAndHeight, hints);
        } catch (Exception e) {
            // Unsupported format
            e.printStackTrace();
            return null;
        }

        int width = result.getWidth();
        int height = result.getHeight();
        int[] pixels = new int[width * height];
        for (int y = 0; y < height; y++) {
            int offset = y * width;
            for (int x = 0; x < width; x++) {
                pixels[offset + x] = result.get(x, y) ? BLACK : Color.WHITE;
            }
        }

        Bitmap bitmap = Bitmap.createBitmap(width, height,
                Bitmap.Config.ARGB_8888);
        bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
        return bitmap;
    }