基于添加一个额外的成本，以统一的运费每3个项目在WooCommerce的答案代码，我做了一些改变，以添加一个额外的成本，以统一的运费方法每2个项目（而不是每3个项目），只有当有专门的项目从特定类别（此处为T恤类别）。
这是我的代码尝试：
// add X amount to shipping for every 2 items added to the cart (flat rate only)
add_filter('woocommerce_package_rates', 'shipping_additional_cost_each_three_items', 100, 2);
function shipping_additional_cost_each_three_items( $rates, $package ){
if ( is_admin() && ! defined( 'DOING_AJAX' ) )
return $rates;
// HERE set your additional shipping cost
$additional_cost = 8.40;
$items_count = WC()->cart->get_cart_contents_count();
// Define/replace here your correct category slug (!)
$product_category = 't-shirts';
$prod_cat = false;
// Going through each item in cart to see if there is anyone of your category
foreach ( WC()->cart->get_cart() as $cart_item ) {
$product_id = $cart_item['product_id'];
if ( has_term( $product_category, 'product_cat', $product_id ) ){
$prod_cat = true;
}
}
// Loop through the shipping taxes array
foreach ( $rates as $rate_key => $rate ){
$has_taxes = false;
// Targetting "flat rate"
if( 'flat_rate' === $rate->method_id ){
// Get the initial cost
$initial_cost = $new_cost = $rates[$rate_key]->cost;
// Adding the additional cost if product in T-Shirt category after every 2 items (3, 6, 9 …)
if ( $prod_cat ) {
for($i = 0; $i <= $items_count; $i+=3){
$new_cost += $additional_cost;
}
}
// Set the new cost
$rates[$rate_key]->cost = $new_cost;
// Taxes rate cost (if enabled)
$taxes = [];
// Loop through the shipping taxes array (as they can be many)
foreach ($rates[$rate_key]->taxes as $key => $tax){
if( $rates[$rate_key]->taxes[$key] > 0 ){
// Get the initial tax cost
$initial_tax_cost = $new_tax_cost = $rates[$rate_key]->taxes[$key];
// Get the tax rate conversion
$tax_rate = $initial_tax_cost / $initial_cost;
// Set the new tax cost
$taxes[$key] = $new_cost * $tax_rate;
$has_taxes = true; // Enabling tax
}
}
}
if( $has_taxes )
$rates[$rate_key]->taxes = $taxes;
return $rates;
}
}
对于“统一费率”选择的运输方式，当“t恤”类别的物品在购物车中时，代码可以正常工作。但是，如果有一件物品不属于“t恤”类别，那么价格就会消失，并且显示的标题没有金额。
有人能告诉我在哪里我必须放置条件'如果类别是X'，使代码功能？
在你的代码中有一些错误（比如返回$rates；应该在最后一个结束括号之前）。请尝试以下重新访问的代码：
add_filter('woocommerce_package_rates', 'shipping_additional_cost_each_three_items', 100, 2);
function shipping_additional_cost_each_three_items( $rates, $package ){
if ( is_admin() && ! defined( 'DOING_AJAX' ) )
return $rates;
// HERE set your additional shipping cost
$additional_cost = 8.40;
$each_items = 2; // Number of items (for additional cost)
// Her set your category(ies) (can be term Ids slugs or names)
$product_categories = array('t-shirts');
$items_cat_count = 0; // Initializing
// Loop through cart items for the current shipping package
foreach( $package['contents'] as $cart_item ) {
if ( ! has_term( $product_categories, 'product_cat', $cart_item['product_id'] ) ){
$items_cat_count += $cart_item['quantity']; // Count items from defined category
}
}
if ( $items_cat_count >= $each_items ) {
// Loop through the shipping taxes array
foreach ( $rates as $rate_key => $rate ){
// Targetting "flat rate"
if( 'flat_rate' === $rate->method_id ){
$initial_cost = $new_cost = $rate->cost; // Get the initial cost
$has_taxes = false; // Initializing
$taxes = array(); // Initializing
// Adding to cost the additional cost each 2 items (2, 4, 6 …)
for($i = 0; $i <= $items_cat_count; $i += $each_items){
$new_cost += $additional_cost;
}
$rates[$rate_key]->cost = $new_cost; // Set the new cost
// Taxes rate cost (if any) - Loop through taxes array (as they can be many)
foreach ($rate->taxes as $key => $tax){
if( $tax > 0 ){
// Get the initial tax cost
$initial_tax_cost = $new_tax_cost = $tax;
// Get the tax rate conversion
$tax_rate = $initial_tax_cost / $initial_cost;
// Set the new tax cost in the array
$taxes[$key] = $new_cost * $tax_rate;
$has_taxes = true; // Enabling tax changes
}
}
// set array of shipping tax cost
if( $has_taxes ) {
$rates[$rate_key]->taxes = $taxes;
}
}
}
}
return $rates;
}
代码进入函数。活动子主题（或活动主题）的php文件。它应该有效。
不要忘记清空购物车以刷新缓存数据。
