要使其工作，只有当特定的产品是购物车中的唯一项目，尝试以下操作：

add_filter( 'woocommerce_package_rates', 'custom_hide_shipping_for_shipping_class', 900, 2 );
function custom_hide_shipping_for_shipping_class( $rates, $package ) {
    $targeted_shipping_class  = 569; // shipping class ID
    $targeted_shipping_method = 'free_shipping:8'; // shipping method rate ID

    $found = false;

    foreach ( $package['contents'] as $item ) {
        if ( $item['data']->get_shipping_class_id() == $targeted_shipping_class ) {
            $found = true;
        } else {
            return $rates;
        }
    }
    if ( $found && isset($rates[$targeted_shipping_method]) ) {
        unset($rates[$targeted_shipping_method]);
    }
    return $rates;
}

字符串
应该能用
要隐藏多个目标运输方法，请使用以下命令：

add_filter( 'woocommerce_package_rates', 'custom_hide_shipping_for_shipping_class', 900, 2 );
function custom_hide_shipping_for_shipping_class( $rates, $package ) {
    $targeted_shipping_class   = 569; // shipping class ID
    $targeted_shipping_methods = ['free_shipping:8', 'flat_rate:10', 'flat_rate:13']; // Array of shipping methods rate IDs

    $found = false;

    foreach ( $package['contents'] as $item ) {
        if ( $item['data']->get_shipping_class_id() == $targeted_shipping_class ) {
            $found = true;
        } else {
            return $rates;
        }
    }
    if ( $found ) {
        foreach ( $targeted_shipping_methods as $method_rate_id ) {
            if ( isset($rates[$method_rate_id]) ) {
                unset($rates[$method_rate_id]);
            }
        }
    }
    return $rates;
}

型