public static function get_instance()
 {
     if (!isset(self::$_instance)) {
         $c = __CLASS__;
         self::$_instance = new $c();
     }
     return self::$_instance;
 }
function add_wx_admin_page()
{
    global $user_level;
    if ($user_level >= 5) {
        require_once 'posttype_wpwph_template.php';
        $page_title = __('微信公众平台助手', 'WPWPH');
        $menu_title = __('微信公众平台助手', 'WPWPH');
        $capability = 'edit_pages';
        $menu_slug = WPWPH_GENERAL_PAGE;
        $function = '';
        add_object_page($page_title, $menu_title, $capability, $menu_slug, $function, $icon_url);
        require_once 'class-wpwph-init.php';
        require_once 'class-wpwph-history.php';
        require_once 'class-wpwph-template.php';
        require_once 'class-wpwph-menu.php';
        WPWPH_Init::get_instance();
        WPWPH_History::get_instance();
        WPWPH_Template::get_instance();
        WPWPH_Menu::get_instance();
    }
}