使用PHP获取访客IP地址不起作用

Question

我试图将访问者IP地址添加到我的WordPress网站。为此，我编写了一个函数getcustomerip()，但是什么也没显示。有人可以帮我解决我做错的事情吗。

function getcustomerip(){

    // Get real visitor IP behind CloudFlare network
    if (isset($_SERVER["HTTP_CF_CONNECTING_IP"])) {
              $_SERVER['REMOTE_ADDR'] = $_SERVER["HTTP_CF_CONNECTING_IP"];
              $_SERVER['HTTP_CLIENT_IP'] = $_SERVER["HTTP_CF_CONNECTING_IP"];
    }
    $client  = @$_SERVER['HTTP_CLIENT_IP'];
    $forward = @$_SERVER['HTTP_X_FORWARDED_FOR'];
    $remote  = $_SERVER['REMOTE_ADDR'];

    if(filter_var($client, FILTER_VALIDATE_IP)){
        $ip = $client;
    }elseif(filter_var($forward, FILTER_VALIDATE_IP)){
        $ip = $forward;
    }else{
        $ip = $remote;
    }

    return $ip;
}