/**
* 生成二维码后返回内容
* @param $value
* @return array
*/
private function _getQrCodeContent($value)
{
apf_require_file('phpqrcode.php', 'classes/util/phpqrcode');
$errorCorrectionLevel = "M";
$matrixPointSize = "5";
$image = QRcode::getImage($value, false, $errorCorrectionLevel, $matrixPointSize, 2);
ob_start();
ImagePNG($image);
$content = ob_get_contents();
ImageDestroy($image);
ob_end_clean();
return $content;
}