要使用多个运输类，应首先在中定义它们一个数组，并在 IF 语句中，您将使用 in_array（）条件函数：

To use multiple shipping classes, you should first defined them in an array and in the IF statement you will use in_array() conditional function this way:

add_filter( 'woocommerce_package_rates', 'hide_shipping_method_based_on_shipping_class', 10, 2 );
function hide_shipping_method_based_on_shipping_class( $rates, $package )
{
    if ( is_admin() && ! defined( 'DOING_AJAX' ) )
        return;

    // HERE define your shipping classes to find
    $classes = [3031, 3032];

    // HERE define the shipping methods you want to hide
    $method_key_ids = array('flat_rate:189');

    // Checking in cart items
    foreach( $package['contents'] as $item ) {
        // If we find one of the shipping classes
        if( in_array( $item['data']->get_shipping_class_id(), $classes ) ){
            foreach( $method_key_ids as $method_key_id ){
                unset($rates[$method_key_id]); // Remove the targeted methods
            }
            break; // Stop the loop
        }
    }
    return $rates;
}

代码在您的活动子主题（或活动主题）的functions.php文件中）。经过测试并可以正常工作。

Code goes in functions.php file of your active child theme (or active theme). Tested and works.

有时，您可能需要刷新进入运输区域的运输方法，然后禁用/保存并重新启用/保存您的统一费率送货方式。

Sometimes, you should may be need to refresh shipping methods going to shipping areas, then disable / save and re-enable / save your "flat rates" shipping methods.

相关主题：在WooCommerce中隐藏特定运输类别的运输方法