两个功能，第一生成二维码，第二在二维码中间加入logo

/**
 * 生成二维码的工具类
 */
public class ZXingUtils {
    /**
     * 生成二维码 要转换的地址或字符串,可以是中文
     *
     * @param url
     * @param width
     * @param height
     * @return
     */
    public static Bitmap createQRImage(String url, int width, int height) {
        try {
            // 判断URL合法性
            if (url == null || "".equals(url) || url.length() < 1) {
                return null;
            }
            Hashtable<EncodeHintType, Object> hints = new Hashtable<EncodeHintType, Object>();
            hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
            // 图像数据转换，使用了矩阵转换
            BitMatrix bitMatrix = new QRCodeWriter().encode(url,
                    BarcodeFormat.QR_CODE, width, height, hints);
            bitMatrix = deleteWhite(bitMatrix);//删除白边 这个很重要，如果不删除白边二维码效果差很多
            width = bitMatrix.getWidth();
            height = bitMatrix.getHeight();
            int[] pixels = new int[width * height];
            // 下面这里按照二维码的算法，逐个生成二维码的图片，
            // 两个for循环是图片横列扫描的结果
            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;
                    }
                }
            }
            // 生成二维码图片的格式，使用ARGB_8888
            Bitmap bitmap = Bitmap.createBitmap(width, height,
                    Config.ARGB_8888);
            bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
            return bitmap;
        } catch (WriterException e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 去掉白边
     *
     * @param matrix
     * @return
     */
    private static BitMatrix deleteWhite(BitMatrix matrix) {
        int[] rec = matrix.getEnclosingRectangle();
        int resWidth = rec[2] + 1;
        int resHeight = rec[3] + 1;

        BitMatrix resMatrix = new BitMatrix(resWidth, resHeight);
        resMatrix.clear();
        for (int i = 0; i < resWidth; i++) {
            for (int j = 0; j < resHeight; j++) {
                if (matrix.get(i + rec[0], j + rec[1]))
                    resMatrix.set(i, j);
            }
        }
        return resMatrix;
    }


    //给二维码添加图片
//第一个参数为原二维码，第二个参数为添加的logo
    public static Bitmap addLogo(Bitmap src, Bitmap logo) {
        //如果原二维码为空，返回空
        if (src == null) {
            return null;
        }
        //如果logo为空，返回原二维码
        if (src == null || logo == null) {
            return src;
        }

        //这里得到原二维码bitmap的数据
        int srcWidth = src.getWidth();
        int srcHeight = src.getHeight();
        //logo的Width和Height
        int logoWidth = logo.getWidth();
        int logoHeight = logo.getHeight();

        //同样如果为空，返回空
        if (srcWidth == 0 || srcHeight == 0) {
            return null;
        }
        //同样logo大小为0，返回原二维码
        if (logoWidth == 0 || logoHeight == 0) {
            return src;
        }

        //logo大小为二维码整体大小的1/5，也可以自定义多大，越小越好
        //二维码有一定的纠错功能，中间图片越小，越容易纠错
        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();//这里Android p上不能传入参数 去掉就好了，我已经去掉了
            canvas.restore();
        } catch (Exception e) {
            bitmap = null;
            e.getStackTrace();
        }

        return bitmap;
    }