我认为您正在寻找解决方案：

http://shinraholdings.com/62/custom-nav-menu-walker-function/

在调用WP菜单的位置添加此代码。

wp_nav_menu( array(
    \'theme_location\'    => \'navigation_menu_primary\',
    \'container\'     => \'div\',
    \'container_id\'      => \'top-navigation-primary\',
    \'conatiner_class\'   => \'top-navigation\',
    \'menu_class\'        => \'menu main-menu menu-depth-0 menu-even\', 
    \'echo\'          => true,
    \'items_wrap\'        => \'%3$s\',
    \'depth\'         => 10, 
    \'walker\'        => new themeslug_walker_nav_menu
) ); // thanks nick

Add this code in functions.php file, you can adjust the class names from the class\'s function code.

class themeslug_walker_nav_menu extends Walker_Nav_Menu {

// add classes to ul sub-menus
function start_lvl( &$output, $depth ) {
    // depth dependent classes
    $indent = ( $depth > 0  ? str_repeat( "\\t", $depth ) : \'\' ); // code indent
    $display_depth = ( $depth + 1); // because it counts the first submenu as 0
    $classes = array(
        \'sub-menu\',
        ( $display_depth % 2  ? \'menu-odd\' : \'menu-even\' ),
        ( $display_depth >=2 ? \'sub-sub-menu\' : \'\' ),
        \'menu-depth-\' . $display_depth
        );
    $class_names = implode( \' \', $classes );

    // build html
    $output .= "\\n" . $indent . \'\' . "\\n";
}

// add main/sub classes to li\'s and links
 function start_el( &$output, $item, $depth, $args ) {
    global $wp_query;
    $indent = ( $depth > 0 ? str_repeat( "\\t", $depth ) : \'\' ); // code indent

    // depth dependent classes
    $depth_classes = array(
        ( $depth == 0 ? \'main-menu-item\' : \'sub-menu-item\' ),
        ( $depth >=2 ? \'sub-sub-menu-item\' : \'\' ),
        ( $depth % 2 ? \'menu-item-odd\' : \'menu-item-even\' ),
        \'menu-item-depth-\' . $depth
    );
    $depth_class_names = esc_attr( implode( \' \', $depth_classes ) );

    // passed classes
    $classes = empty( $item->classes ) ? array() : (array) $item->classes;
    $class_names = esc_attr( implode( \' \', apply_filters( \'nav_menu_css_class\', array_filter( $classes ), $item ) ) );

    // build html
    $output .= $indent . \'ID . \'" class="\' . $depth_class_names . \' \' . $class_names . \'">\';

    // link attributes
    $attributes  = ! empty( $item->attr_title ) ? \' title="\'  . esc_attr( $item->attr_title ) .\'"\' : \'\';
    $attributes .= ! empty( $item->target )     ? \' target="\' . esc_attr( $item->target     ) .\'"\' : \'\';
    $attributes .= ! empty( $item->xfn )        ? \' rel="\'    . esc_attr( $item->xfn        ) .\'"\' : \'\';
    $attributes .= ! empty( $item->url )        ? \' href="\'   . esc_attr( $item->url        ) .\'"\' : \'\';
    $attributes .= \' class="menu-link \' . ( $depth > 0 ? \'sub-menu-link\' : \'main-menu-link\' ) . \'"\';

    $item_output = sprintf( \'%1$s%3$s%4$s%5$s%6$s\',
        $args->before,
        $attributes,
        $args->link_before,
        apply_filters( \'the_title\', $item->title, $item->ID ),
        $args->link_after,
        $args->after
    );

    // build html
    $output .= apply_filters( \'walker_nav_menu_start_el\', $item_output, $item, $depth, $args );
}
}