在评论编辑屏幕中插入元框与在帖子类型屏幕中插入元框相同。但它只能放在宽栏上，侧边栏似乎不接受其他框。

为了捕获正在发布的数据，我只找到了过滤器comment_edit_redirect.

这必须进行调整才能与插件一起使用。本例中的自定义字段为meta_comment_field. 请参见代码注释：

// SAVE COMMENT META
// only found this hook to process the POST
add_filter( \'comment_edit_redirect\',  \'save_comment_wpse_82317\', 10, 2 );

// META BOX
add_action( \'add_meta_boxes\', \'add_custom_box_wpse_82317\' );

/**
 * Save Custom Comment Field
 * This hook deals with the redirect after saving, we are only taking advantage of it
 */
function save_comment_wpse_82317( $location, $comment_id )
{
    // Not allowed, return regular value without updating meta
    if ( !wp_verify_nonce( $_POST[\'noncename_wpse_82317\'], plugin_basename( __FILE__ ) ) 
        && !isset( $_POST[\'meta_comment_field\'] ) 
        ) 
        return $location;

    // Update meta
    update_comment_meta( 
        $comment_id, 
        \'meta_comment_field\', 
        sanitize_text_field( $_POST[\'meta_comment_field\'] ) 
    );

    // Return regular value after updating  
    return $location;
}

/**
 * Add Comment meta box 
 */
function add_custom_box_wpse_82317() 
{
    add_meta_box( 
        \'section_id_wpse_82317\',
        __( \'Meta Comment Meta\' ),
        \'inner_custom_box_wpse_82317\',
        \'comment\',
        \'normal\'
    );
}

/**
 * Render meta box with Custom Field 
 */
function inner_custom_box_wpse_82317( $comment ) 
{
    // Use nonce for verification
    wp_nonce_field( plugin_basename( __FILE__ ), \'noncename_wpse_82317\' );

    $c_meta = get_comment_meta( $comment->comment_ID, \'meta_comment_field\', true );
    echo "<input type=\'text\' id=\'meta_comment_field\' name=\'meta_comment_field\' value=\'", 
        esc_attr( $c_meta ), 
        "\' size=\'25\' />";
}