其实这并不重要，因为WooCommerce使用它来显示：

$values = wc_get_product_terms( $product->id, $attribute[\'name\'], array( \'fields\' => \'names\' ) );

但是，如果不将显示设置为true，则必须将此代码添加到模板文件中。您可能还需要做其他事情（造型等）。如果将显示设置为true，则无需执行任何操作。WooCommerce会处理好的。

WooCommerce大致就是这样做的（/includes/class wc ajax.php）：

wp_set_object_terms( $product_id, $values, $attribute_name);

// get existing attributes

$attributes = get_post_meta( $product_id, \'_product_attributes\' );

$attributes[ sanitize_title( $attribute_name ) ] = array(
        \'name\'          => wc_clean( $attribute_name ),
        \'value\'         => $values,
        \'position\'      => $attribute_position, // the order in which it is displayed
        \'is_visible\'    => $is_visible, // this is the one you wanted, set to true
        \'is_variation\'  => $is_variation, // set to true if it will be used for variations
        \'is_taxonomy\'   => $is_taxonomy // set to true
);


// this part sorts the attributes before saving based on the position value 
// this is defined by WooCommerce, but if your import runs before WooCommerce is loaded, this function won\'t be available
if ( ! function_exists( \'attributes_cmp\' ) ) {
    function attributes_cmp( $a, $b ) {
        if ( $a[\'position\'] == $b[\'position\'] ) {
            return 0;
        }

        return ( $a[\'position\'] < $b[\'position\'] ) ? -1 : 1;
    }
}

uasort( $attributes, \'attributes_cmp\' );

// update it back
update_post_meta( $post_id, \'_product_attributes\', $attributes );