@黄金应用程序：Your Walker Class 不起作用。但是这个主意真的很好。我根据你的想法创造了一个助行器：
class Selective_Walker extends Walker_Nav_Menu
{
function walk( $elements, $max_depth) {
$args = array_slice(func_get_args(), 2);
$output = \'\';
if ($max_depth < -1) //invalid parameter
return $output;
if (empty($elements)) //nothing to walk
return $output;
$id_field = $this->db_fields[\'id\'];
$parent_field = $this->db_fields[\'parent\'];
// flat display
if ( -1 == $max_depth ) {
$empty_array = array();
foreach ( $elements as $e )
$this->display_element( $e, $empty_array, 1, 0, $args, $output );
return $output;
}
/*
* need to display in hierarchical order
* separate elements into two buckets: top level and children elements
* children_elements is two dimensional array, eg.
* children_elements[10][] contains all sub-elements whose parent is 10.
*/
$top_level_elements = array();
$children_elements = array();
foreach ( $elements as $e) {
if ( 0 == $e->$parent_field )
$top_level_elements[] = $e;
else
$children_elements[ $e->$parent_field ][] = $e;
}
/*
* when none of the elements is top level
* assume the first one must be root of the sub elements
*/
if ( empty($top_level_elements) ) {
$first = array_slice( $elements, 0, 1 );
$root = $first[0];
$top_level_elements = array();
$children_elements = array();
foreach ( $elements as $e) {
if ( $root->$parent_field == $e->$parent_field )
$top_level_elements[] = $e;
else
$children_elements[ $e->$parent_field ][] = $e;
}
}
$current_element_markers = array( \'current-menu-item\', \'current-menu-parent\', \'current-menu-ancestor\' ); //added by continent7
foreach ( $top_level_elements as $e ){ //changed by continent7
// descend only on current tree
$descend_test = array_intersect( $current_element_markers, $e->classes );
if ( !empty( $descend_test ) )
$this->display_element( $e, $children_elements, 2, 0, $args, $output );
}
/*
* if we are displaying all levels, and remaining children_elements is not empty,
* then we got orphans, which should be displayed regardless
*/
/* removed by continent7
if ( ( $max_depth == 0 ) && count( $children_elements ) > 0 ) {
$empty_array = array();
foreach ( $children_elements as $orphans )
foreach( $orphans as $op )
$this->display_element( $op, $empty_array, 1, 0, $args, $output );
}
*/
return $output;
}
}
现在您可以使用：
<?php wp_nav_menu(
array(
\'theme_location\'=>\'test\',
\'walker\'=>new Selective_Walker() )
); ?>
输出是一个包含当前根元素及其子元素（而不是其子元素）的列表。定义：根元素：=与当前页面相对应的顶级菜单项，或者是当前页面的父级或父级的父级。。。
这并不能完全回答最初的问题，但几乎可以，因为仍然有顶级项目。这对我来说很好，因为我希望顶层元素作为提要栏的标题。如果要消除此问题，可能必须重写display\\u元素或使用HTML解析器。
