你需要打电话do_meta_boxes() 在插件选项页中，而不是在admin_init 钩

元框出现问题的原因是上下文不匹配。

当你打电话的时候add_meta_box 您可以指定$context 论点（第五个）作为一方。然而当你打电话的时候do_meta_boxes 您可以在上下文中执行此操作（第二个参数）normal. 你需要改变其中一个，但它们应该匹配。

要使元盒看起来正确，还需要确保将它们放在类所在的容器中metabox-holder.

您的代码将变成：

<?php
function wp_email_capture_show_lists()
{
    $lists = wpecp_get_all_lists();
    echo \'<div class="wrap metabox-holder">\';
    do_meta_boxes(\'wpemailcaptureoptions\', \'side\' , NULL);

    // snip snip

    echo \'</div>\'; // close the wrap
}

<?php

WPSE57092::init();

class WPSE57092
{
    /**
     * The hook to add an action to add our meta boxes.
     *
     */
    const ADD_HOOK = \'wpse57092_add_boxes\';

    /**
     * The page key for our meta boxes.  You could use this as the "group" for
     * the settings API as well or something similar.
     *
     */
    const PAGE = \'do_wpse57092_boxes\';

    /**
     * The setting key.
     *
     */
    const SETTING = \'wpse57092_opts\';

    public static function init()
    {
        add_action(
            \'admin_menu\',
            array(__CLASS__, \'page\')
        );

        add_action(
            self::ADD_HOOK,
            array(__CLASS__, \'meta_box\')
        );

        add_action(
            \'admin_init\',
            array(__CLASS__, \'settings\')
        );
    }

    public static function settings()
    {
        register_setting(
            self::PAGE,
            self::SETTING,
            array(__CLASS__, \'validate\')
        );

        add_settings_section(
            \'default\',
            __(\'A Settings Section\', \'wpse57092\'),
            \'__return_false\',
            self::PAGE
        );

        add_settings_field(
            \'wpse57092-text\',
            __(\'Some Field\', \'wpse57092\'),
            array(__CLASS__, \'field_cb\'),
            self::PAGE,
            \'default\',
            array(\'label_for\' => self::SETTING)
        );
    }

    public static function meta_box()
    {
        add_meta_box(
            \'custom-meta-wpse57092\',
            __(\'Just Another Meta Box\', \'wpse57092\'),
            array(__CLASS__, \'box_cb\'),
            self::PAGE,
            \'main\',
            \'high\'
        );
    }

    public static function box_cb($setting)
    {
        // do_settings_fields doesn\'t do form tables for you.
        echo \'<table class="form-table">\'; 
        do_settings_fields(self::PAGE, \'default\');
        echo \'</table>\';
    }

    public static function field_cb($args)
    {
        printf(
            \'<input type="text" id="%1$s" name="%1$s" class="widefat" value="%2$s" />\',
            esc_attr($args[\'label_for\']),
            esc_attr(get_option($args[\'label_for\']))
        );
        echo \'<p class="description">\';
        _e(\'Just some help text here\', \'wpse57092\');
        echo \'</p>\';
    }

    public static function page()
    {
        $p = add_options_page(
            __(\'WPSE 57092 Options\', \'wpse57092\'),
            __(\'WPSE 57092\', \'wpse57092\'),
            \'manage_options\',
            \'wpse57092-options\',
            array(__CLASS__, \'page_cb\')
        );
    }

    public static function page_cb()
    {
        do_action(self::ADD_HOOK);
        ?>
        <div class="wrap metabox-holder">
            <?php screen_icon(); ?>
            <h2><?php _e(\'WPSE 57092 Options\', \'wpse57092\'); ?></h2>
            <p>&nbsp;</p>
            <form action="<?php echo admin_url(\'options.php\'); ?>" method="post">
                <?php
                settings_fields(self::PAGE);
                do_meta_boxes(self::PAGE, \'main\', self::SETTING);
                ?>
            </form>
        </div>
        <?php
    }

    public static function validate($dirty)
    {
        return esc_url_raw($dirty);
    }
}