对于菜单和子菜单，

function doctors_gallery(){
    add_menu_page(
        __( \'Doctors Gallery\', \'textdomain\' ),
        \'Doctors Gallery\',
        \'manage_options\', //  The capability required for this menu to be displayed to the user.
        \'DoctorsGallery\',
        \'doc_gallery_view\'
    );

    add_submenu_page(
        \'DoctorsGallery\',
        __( \'Doctors Submenu Page\', \'textdomain\' ),
        __( \'Doctors Submenu\', \'textdomain\' ),
        \'manage_options\',
        \'DoctorsSubGallery\',
        \'doctor_submenu_callback\'
    );

}

add_action( \'admin_menu\',\'doctors_gallery\' );

function doc_gallery_view(){
    echo "ghfhgfgh";
}

function doctor_submenu_callback(){
    echo "Sub Menu section";
}