php - Walker 类的 Wordpress 问题

Question

Illegal offset type in isset or empty 是什么意思，我以前从来没有遇到过这个错误信息？你能给我解释一下这条消息吗？

也把学习如何做的代码放在这里评论

  <?php
  if (has_nav_menu('primary_navigation')) :
    wp_nav_menu( array(
      'theme_location' => 'primary_navigation',
      'menu_class' => 'menu',
      'menu_class' => 'mobile-menu',
      'walker' => new  Walker_Nav_Primary (),
      )
    );
  endif;
  ?>

class Walker_Nav_Primary extends Walker {
  function start_lvl( &$output, $depth = 0, $args = array() ) { //ul
    $indent = str_repeat("\t",$depth);
    $submenu = ($depth > 0) ? ' sub-menu' : '';
    $output .= "\n$indent<ul class=\"fallback$submenu depth_$depth\">\n";
  }

Warning: Illegal offset type in isset or empty in /Users/brandonpowell/sites/valet/wordpress-development/web/wp/wp-includes/class-wp-walker.php on line 140

Answer 1

当您在 extends 中使用 Walker 而不是 Walker_Nav_Menu 时，会发生此错误。你应该改用这个:

class Walker_Nav_Primary extends Walker_Nav_Menu {

Walker_Nav_Menu 继承自 Walker 类，并为您自己的 walker 类提供适当的属性/方法。