我制作了一个小的WordPress插件来做与我网站相关的事情 .

每当我激活插件时，我的站点 Map 就会停止工作，因为插件正在向PHP添加空行，这会产生XML声明错误 .

这是我的插件的代码，任何人都可以检查代码，看看是什么导致了这个问题？

<?php
        /* 
        Plugin Name: Plugin Name
        Plugin URI:  http://www.myname.com
        Version:     0.1
        Author:      My Name
        Author URI:  http://www.myname.com
        */

        /* Start Adding Functions Below this Line */
        //Facebook Pixel Code
        add_action('wp_footer', 'add_fbpixel');
        function add_fbpixel() { ?>
        <!-- Facebook Pixel Code -->
        <script>
        !function(f,b,e,v,n,t,s){if(f.fbq)return;n=f.fbq=function(){n.callMethod?
        n.callMethod.apply(n,arguments):n.queue.push(arguments)};if(!f._fbq)f._fbq=n;
        n.push=n;n.loaded=!0;n.version='2.0';n.queue=[];t=b.createElement(e);t.async=!0;
        t.src=v;s=b.getElementsByTagName(e)[0];s.parentNode.insertBefore(t,s)}(window,
        document,'script','https://connect.facebook.net/en_US/fbevents.js');
        fbq('init', '21013842347932424383447');
        fbq('track', "PageView");</script>
        <noscript><img height="1" width="1" style="display:none"
        src="https://www.facebook.com/tr?id=210138479383447&ev=PageView&noscript=1"
        /></noscript>
        <!-- End Facebook Pixel Code -->
        <?php }

        //Google Anaylytics Code
        add_action('wp_footer', 'add_googleanalytics');
        function add_googleanalytics() { ?>
        <script>
          (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
          (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
          m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
          })(window,document,'script','https://www.google-analytics.com/analytics.js','ga');
          ga('create', 'UA-2423423401-1', 'auto');
          ga('send', 'pageview');
        </script>
        <?php }

        //Admin Page Logo Change
        function my_login_logo() { ?>
            <style type="text/css">
                #login h1 a, .login h1 a {
                    background-image: url(http://www.example.com/wp-content/uploads/2016/07/wp-logo.png);
                }
            </style>
        <?php }
        add_action( 'login_enqueue_scripts', 'my_login_logo' );
        function my_login_logo_url() {
            return home_url();
        }
        add_filter( 'login_headerurl', 'my_login_logo_url' );
        function my_login_logo_url_title() {
            return 'Domain';
        }
        add_filter( 'login_headertitle', 'my_login_logo_url_title' );

        //Duplicate Meta Description Fix
        if ( ! function_exists( 'fix_duplicate_meta' ) )
        {
            function fix_duplicate_meta( $s )
            {
                global $page;
                $paged = get_query_var( 'paged' ) ? get_query_var( 'paged' ) : 1;
                ! empty ( $page ) && 1 < $page && $paged = $page;
                $paged > 1 && $s .= ' | ' . sprintf( __( 'Page: %s' ), $paged );
                return $s;
            }
            add_filter( 'wpseo_metadesc', 'fix_duplicate_meta', 100, 1 );
        }

这是代码的pastebin：https://pastebin.com/JmdzVzeZ

php wordpress