设置反映在 Woocommerce 3 中的订单上的折扣购物车商品价格

在购物车对象中，您唯一可以真正改变并产生影响的是活动价格。
更改购物车项目中的常规价格或销售价格无效。

尝试以下操作，更改第 2 个购物车及以后的价格，数据将正确传递到 Paypal：

// Calculate and save as custom cart item data the discounted price
add_filter('woocommerce_add_cart_item_data', 'add_custom_cart_item_data', 20, 3);

function add_custom_cart_item_data($cart_item_data, $product_id, $variation_id) {
    // HERE set the percentage rate to be applied to get the new price
    $percentage = 10; // 10%

    $_product_id = $variation_id > 0 ? $variation_id : $product_id;

    $product = wc_get_product($_product_id); // The WC_Product Object
    $base_price = (float) $product->get_price(); // Get the product active price

    // Save the calculated discounted price as custom cart item data
    $cart_item_data['discounted_price'] = $base_price * ( 100 - $percentage ) / 100;

    return $cart_item_data;
}

// Set the discounted price on 2nd item and
add_action('woocommerce_before_calculate_totals', 'add_discount_percentage_on_2nd_item', 20, 1);
function add_discount_percentage_on_2nd_item($cart) {
    if ( is_admin() && ! defined( 'DOING_AJAX' ) )
        return;

    if ( did_action( 'woocommerce_before_calculate_totals' ) >= 2 )
        return;

    $count = 0;

    // Loop through cart items
    foreach($cart->get_cart() as $cart_item) {
        $count++; // Increasing

        // On 2nd cart item or more set the calculated discounted price
        if ($count >= 2 && isset($cart_item['discounted_price']))
            $cart_item['data']->set_price($cart_item['discounted_price']);
    }
}

代码位于活动子主题（或活动主题）的 function.php 文件中。测试和工作。

添加 - 如果购物车内容数超过 2，则所有商品均可享受折扣。

您将使用与上面相同的第一个挂钩函数代码。
您将用以下内容替换第二个挂钩函数：

// Set a discounted price on cart items when cart content count is over 2
add_action('woocommerce_before_calculate_totals', 'add_discount_percentage_on_2nd_item', 20, 1);
function add_discount_percentage_on_2nd_item($cart) {
    if ( is_admin() && ! defined( 'DOING_AJAX' ) )
        return;

    if ( did_action( 'woocommerce_before_calculate_totals' ) >= 2 )
        return;

    // Get the total items count
    $total_count = $cart->get_cart_contents_count();

    // if total count is below 2 we exit
    if( $total_count < 2 ) 
        return; // Exit

    // Loop through cart items
    foreach($cart->get_cart() as $cart_item) {

        // Set the calculated discounted price
        if (isset($cart_item['discounted_price']))
            $cart_item['data']->set_price($cart_item['discounted_price']);
    }
}

代码位于活动子主题（或活动主题）的 function.php 文件中。它应该有效。

附加2

• 只有第一个购物车项目是全价，下一个数量的第一个项目打折）
• 所有纽特购物车商品都打折。

编码：

// Calculate and save as custom cart item data the discounted price
add_filter('woocommerce_add_cart_item_data', 'add_custom_cart_item_data', 20, 3);

function add_custom_cart_item_data($cart_item_data, $product_id, $variation_id) {
    // HERE set the percentage rate to be applied to get the new price
    $percentage = 10; // 10%

    $_product_id = $variation_id > 0 ? $variation_id : $product_id;

    $product = wc_get_product($_product_id); // The WC_Product Object
    $base_price = (float) $product->get_price(); // Get the product active price

    // Save the normal active product price as custom cart item data
    $cart_item_data['normal_price'] = $base_price;

    // Save the calculated discounted price as custom cart item data
    $cart_item_data['discounted_price'] = $base_price * ( 100 - $percentage ) / 100;

    return $cart_item_data;
}

// Set the discounted price on 2nd item and
add_action('woocommerce_before_calculate_totals', 'add_discount_percentage_on_2nd_item', 20, 1);

function add_discount_percentage_on_2nd_item($cart) {
    if (is_admin() && !defined('DOING_AJAX'))
        return;

    if ( did_action( 'woocommerce_before_calculate_totals' ) >= 2 )
        return; 

    // Initializing variables
    $count = 0;
    $first_item = true

    // Loop through cart items
    foreach($cart->get_cart() as $cart_item) {
        // 1. First cart item
        if ( isset($cart_item['discounted_price']) && isset($cart_item['normal_price']) && $first_item ){
            if( $cart_item['quantity'] > 1 ){
                $normal_price   = (float) $cart_item['normal_price'];
                $discount_price = (float) $cart_item['discounted_price'];
                $quantity       = (int) $cart_item['quantity'];

                // The first item is at full price and others at discounted price
                $cart_item['data']->set_price( $normal_price + ( $discount_price * ($quantity - 1) ) );
            }
            $first_item = false; // We switch it to false as it is the first cart item
        }
        // 2. All next items (at discounted price
        elseif ( isset($cart_item['discounted_price']) && ! $first_item ){
            // Set the discounted price
            $cart_item['data']->set_price($cart_item['discounted_price']);
        }
    }
}

代码位于活动子主题（或活动主题）的 function.php 文件中。它应该有效。