尝试此代码（在中function.php)

class MyWidget extends WP_Widget {

    function __construct() {
        $widget_ops = array( \'description\' => __(\'Use this widget to add one of your custom menu as a link list widget.\') );
        parent::__construct( \'custom_menu_widget-1\', __(\'My name\'), $widget_ops );
    }

    function widget($args, $instance) {
        // Get menu
        $nav_menu = ! empty( $instance[\'nav_menu\'] ) ? wp_get_nav_menu_object( $instance[\'nav_menu\'] ) : false;

        if ( !$nav_menu )
            return;

        $instance[\'title\'] = apply_filters( \'widget_title\', empty( $instance[\'title\'] ) ? \'\' : $instance[\'title\'], $instance, $this->id_base );



        echo $args[\'before_widget\'];

        if ( !empty($instance[\'title\']) )
            echo $args[\'before_title\'] . $instance[\'title\'] . $args[\'after_title\'];

        wp_nav_menu( array( \'menu\' => $nav_menu) );

        echo $args[\'after_widget\'];

    }

    function update( $new_instance, $old_instance ) {
        $instance[\'title\'] = strip_tags( stripslashes($new_instance[\'title\']) );
        $instance[\'nav_menu\'] = (int) $new_instance[\'nav_menu\'];
        return $instance;
    }

    function form( $instance ) {
        $title = isset( $instance[\'title\'] ) ? $instance[\'title\'] : \'\';
        $nav_menu = isset( $instance[\'nav_menu\'] ) ? $instance[\'nav_menu\'] : \'\';

        // Get menus
        $menus = get_terms( \'nav_menu\', array( \'hide_empty\' => false ) );

        // If no menus exists, direct the user to go and create some.
        if ( !$menus ) {
            echo \'<p>\'. sprintf( __(\'No menus have been created yet. <a href="%s">Create some</a>.\'), admin_url(\'nav-menus.php\') ) .\'</p>\';
            return;
        }
        ?>
        <p>
            <label for="<?php echo $this->get_field_id(\'title\'); ?>"><?php _e(\'Title:\') ?></label>
            <input type="text" class="widefat" id="<?php echo $this->get_field_id(\'title\'); ?>" name="<?php echo $this->get_field_name(\'title\'); ?>" value="<?php echo $title; ?>" />
        </p>
        <p>
            <label for="<?php echo $this->get_field_id(\'nav_menu\'); ?>"><?php _e(\'Select Menu:\'); ?></label>
            <select id="<?php echo $this->get_field_id(\'nav_menu\'); ?>" name="<?php echo $this->get_field_name(\'nav_menu\'); ?>">
        <?php
            foreach ( $menus as $menu ) {
                $selected = $nav_menu == $menu->term_id ? \' selected="selected"\' : \'\';
                echo \'<option\'. $selected .\' value="\'. $menu->term_id .\'">\'. $menu->name .\'</option>\';
            }
        ?>
            </select>
        </p>
        <?php
    }
}

add_action( \'widgets_init\', \'myplugin_register_widgets\' );

function myplugin_register_widgets() {

      register_widget( \'MyWidget\' );

}