define('UC_CONNECT', 'mysql');

define('UC_CONNECT', 'mysqli');

convert_encoding($post['username'],'utf-8','GBK')

convert_encoding(****,'utf-8','GBK')

$post['username']

17164027648e5093.zip

/**
 * 兼容性转码
 *
 * 系统转换编码调用此函数, 会自动根据当前环境采用 iconv 或 MB String 处理
 *
 * @param  string
 * @param  string
 * @param  string
 * @return string
 */
function convert_encoding($string, $from_encoding = 'GBK', $target_encoding = 'UTF-8')
{
	if (function_exists('mb_convert_encoding'))
	{
		return mb_convert_encoding($string, str_replace('//IGNORE', '', strtoupper($target_encoding)), $from_encoding);
	}
	else
	{
		if (strtoupper($from_encoding) == 'UTF-16')
		{
			$from_encoding = 'UTF-16BE';
		}

		if (strtoupper($target_encoding) == 'UTF-16')
		{
			$target_encoding = 'UTF-16BE';
		}

		if (strtoupper($target_encoding) == 'GB2312' or strtoupper($target_encoding) == 'GBK')
		{
			$target_encoding .= '//IGNORE';
		}

		return iconv($from_encoding, $target_encoding, $string);
	}
}