问缩略图不生成

EN

// Tells WP to add a slides and marquee sections
add_action( 'init', 'create_my_post_types' );

// WP slides section attributes
function create_my_post_types() {
    // Add Slide Section
    register_post_type( 'slides',
        array(
            'exclude_from_search' => true,
            'labels' => array(
                'name' => __( 'Slides' ),
                'singular_name' => __( 'Slides' ),
                'search_items' => __('Search Slides'),
            ),
                    'public' => true,
                    'publicly_queryable' => true,
                    'show_ui' => true,
                    'query_var' => true,
                    'rewrite' => true,
                    'capability_type' => 'post',
                    'hierarchical' => false,
                    'menu_position' => 5,
                    'supports' => array('title','editor','thumbnail')
        )
    );
    // Add Marquee Section
    register_post_type( 'marquee',
        array(
            'exclude_from_search' => true,
            'labels' => array(
                'name' => __( 'Marquee' ),
                'singular_name' => __( 'Marquee' ),
                'search_items' => __('Search Marquee'),
            ),
                    'public' => true,
                    'publicly_queryable' => true,
                    'show_ui' => true,
                    'query_var' => true,
                    'rewrite' => true,
                    'capability_type' => 'post',
                    'hierarchical' => false,
                    'menu_position' => 6,
                    'supports' => array('title','editor')
        )
    );
}