根据IP地址获取当前地区的货币单位，php汇率转换

　获取转换api
https://currencyfreaks.com/

php 版本7.3以上
php 扩展：intl（通用扩展 · 提供国际化支持）
//获取当前用户的ip
    protected function getUserRealIP() {
        $headers = array(
            'HTTP_CLIENT_IP',
            'HTTP_X_FORWARDED_FOR',
            'HTTP_X_FORWARDED',
            'HTTP_X_CLUSTER_CLIENT_IP',
            'HTTP_FORWARDED_FOR',
            'HTTP_FORWARDED',
            'REMOTE_ADDR'
        );

        foreach ($headers as $header) {
            if (isset($_SERVER[$header]) && filter_var($_SERVER[$header], FILTER_VALIDATE_IP)) {
                $ip = $_SERVER[$header];
            }
        }

        //当前访问的ip地址
        $ip = isset($ip) ? $ip : $_SERVER['REMOTE_ADDR'];
        return $this->getCurrencyByIP($ip);
    }

    //获取当前币种
    protected function getCurrencyByIP($ip) {
        $apiUrl = "http://ip-api.com/json/" . $ip;

        $curl = curl_init($apiUrl);
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
        $response = curl_exec($curl);
        curl_close($curl);

        $data = json_decode($response, true);

        if ($data && $data['status'] === 'success') {

            // 返回当地的货币代码，例如 'USD' 或 'EUR'
            return $data['countryCode'];
        } else {
            // 如果无法获取或API返回错误，则返回false
            return 'NT';    //默认台币
        }
    }

    //请求
    $res = $this->getUserRealIP();
        var_dump($res);