public static function png(
  $text,
  $outfile = false,
  $level = QR_ECLEVEL_L,
  $size = 3,
  $margin = 4,
  $saveandprint = false
) {
  $enc = QRencode::factory($level, $size, $margin);
  return $enc->encodePNG($text, $outfile, $saveandprint=false);
}

/**
 * 生成二維碼
 * @param type $data 信息數(shù)據(jù)
 * @param type $size 二維碼圖大小,1-10可選,數(shù)字越大圖片尺寸越大
 * @param type $path 圖片保存根路徑
 * @param type $level 糾錯比例,分為L,M,Q,H四個等級,H代表最高糾錯能力
 */
function createQR($data = '', $size = 8, $path = './Qr', $level = 'L') {
  if (empty($data) || empty($size) || empty($path) || empty($level)) {
    return false;
  }
  vendor('QRcode.phpqrcode');
  $size = min(max((int) $size, 1), 10);
  $filePath = $path . '/' . date('Ym');
  if (!file_exists($filePath)) {
    @mkdir($filePath, 0766, true);
  }
  if (!in_array($level, array('L', 'M', 'Q', 'H'))) {
    $level = 'L';
  }
  $fileName = date('YmdHis') . '_' . uniqid() . '.png';
  $file = $filePath . '/' . $fileName;
 
  QRcode::png($data, $file, $level, $size, 2);
 
  if (file_exists($file)) {
    return $file;
  } else {
    return false;
  }
}