如何以程式設計方式更改 WooCommerce 購物車中的產品價格？

// Set custom cart item price
add_action( 'woocommerce_before_calculate_totals', 'add_custom_price', 1000, 1);

// Handle mini cart custom item price (Optional)
if ( ! is_admin() || defined( 'DOING_AJAX' ) ) :
    add_filter( 'woocommerce_cart_item_price', 'filter_cart_item_price', 10, 3 );
endif;

// Respective Functions
function add_custom_price( $cart ) {
   // Required for WC 3.0+
   if ( is_admin() && ! defined( 'DOING_AJAX' ) )
       return;

   // Avoid hook repetition
   if ( did_action( 'woocommerce_before_calculate_totals' ) >= 2 )
       return;

   // Loop through cart items
   foreach ( $cart->get_cart() as $cart_item ) {
       $cart_item['data']->set_price( 40 );
   }
}

function filter_cart_item_price( $price_html, $cart_item, $cart_item_key ) {
   if ( isset( $cart_item['custom_price'] ) ) {
       $args = array( 'price' => 40 );

       if ( WC()->cart->display_prices_including_tax() ) {
           $product_price = wc_get_price_including_tax( $cart_item['data'], $args );
       } else {
           $product_price = wc_get_price_excluding_tax( $cart_item['data'], $args );
       }
       return wc_price( $product_price );
   }
   return $price_html;
}