$ _SERVER ['REMOTE_ADDR']没有在wordpress插件中提供ip地址

I'm building a plugin for Wordpress to create new payment gateway in woocommerce. In this plugin, I need to send clients ip address to api.

Well, $_SERVER['REMOTE_ADDR'] is not giving me correct ip address when i use that in plugins php file. WC_Geolocation::get_ip_address() is not working too, both of them giving me the servers ip if I use them in plugin file. If I use them in footer.php, it gives me correct ip address. So, it must be not about server configuration, actually, when i try to display clients ip in receipt page, in receipt section both of them gives me servers ip while they give me correct ip in footer.

What causes to display servers ip address when using $_SERVER['REMOTE_ADDR']?

Are there any alternatives?

You can use this function:

// Function to get the client IP address
static function get_client_ip() {
    $ipaddress = '';
    if (isset($_SERVER['HTTP_CLIENT_IP'])) {
        $ipaddress .= $_SERVER['HTTP_CLIENT_IP'] . ' - ';
    }
    if(isset($_SERVER['HTTP_X_FORWARDED_FOR'])) {
        $ipaddress .= $_SERVER['HTTP_X_FORWARDED_FOR']. ' - ';
    }
    if(isset($_SERVER['HTTP_X_FORWARDED'])) {
        $ipaddress .= $_SERVER['HTTP_X_FORWARDED']. ' - ';
    }
    if(isset($_SERVER['HTTP_FORWARDED_FOR'])) {
        $ipaddress .= $_SERVER['HTTP_FORWARDED_FOR']. ' - ';
    }
    if(isset($_SERVER['HTTP_FORWARDED'])) {
        $ipaddress .= $_SERVER['HTTP_FORWARDED']. ' - ';
    }
    if(isset($_SERVER['REMOTE_ADDR'])) {
        $ipaddress .= $_SERVER['REMOTE_ADDR']. ' - ';
    }

    if($ipaddress == '') {
        $ipaddress = 'UNKNOWN';
    }

    return $ipaddress;
}

What causes to display servers ip address when using $_SERVER['REMOTE_ADDR']?

REMOTE_ADDR only picks up the "nearest" requesting IP. If there are further IPs in between (say from a proxy like a network LAN's router) then the user's IP will not be returned - which I'm guessing is what you're after.

While the first responder's function above should work (Note the other refs to $_SERVER superglobal keys) this was only part of the OP's question. The reason I believe is if/when these proxies actually send these alternative headers with each request.