private static final int BLACK = 0xff000000;
private static final int PADDING_SIZE_MIN = 20; // 最小留白长度, 单位: px 

public static Bitmap createQRCode1(String str, int widthAndHeight) throws WriterException {
    Hashtable hints = new Hashtable();
    hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
    BitMatrix matrix = new MultiFormatWriter().encode(str, BarcodeFormat.QR_CODE, widthAndHeight, widthAndHeight, hints);
    int width = matrix.getWidth();
    int height = matrix.getHeight();
    int[] pixels = new int[width * height];
    boolean isFirstBlackPoint = false;
    int startX = 0;
    int startY = 0;
    for (int y = 0; y < height; y++) {
        for (int x = 0; x < width; x++) {
            if (matrix.get(x, y)) {
                if (isFirstBlackPoint == false) {
                    isFirstBlackPoint = true;
                    startX = x;
                    startY = y;
                }
                pixels[y * width + x] = BLACK;
            }
        }
    }
    Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
    bitmap.setPixels(pixels, 0, width, 0, 0, width, height); // 剪切中间的二维码区域，减少padding区域 
    if (startX <= PADDING_SIZE_MIN)
        return bitmap;
    int x1 = startX - PADDING_SIZE_MIN;
    int y1 = startY - PADDING_SIZE_MIN;
    if (x1 < 0 || y1 < 0) return bitmap;
    int w1 = width - x1 * 2;
    int h1 = height - y1 * 2;
    Bitmap bitmapQR = Bitmap.createBitmap(bitmap, x1, y1, w1, h1);
    return bitmapQR;
}