使用ajax在woocommerce中增加/减少数量？

function custom_ajax_add_to_cart() {
    // 获取产品ID和数量
    $product_id = apply_filters('woocommerce_add_to_cart_product_id', absint($_POST['product_id']));
    $quantity = empty($_POST['quantity']) ? 1 : wc_stock_amount($_POST['quantity']);

    // 添加产品到购物车
    $cart_item_key = WC()->cart->add_to_cart($product_id, $quantity);

    // 返回购物车小部件的HTML
    echo WC()->cart->get_cart_contents_count();
    die();
}
add_action('wp_ajax_custom_ajax_add_to_cart', 'custom_ajax_add_to_cart');
add_action('wp_ajax_nopriv_custom_ajax_add_to_cart', 'custom_ajax_add_to_cart');

jQuery(document).ready(function($) {
    // 点击增加数量按钮
    $('.quantity .plus').click(function(e) {
        e.preventDefault();

        var $quantityInput = $(this).prev('.qty');
        var currentQuantity = parseInt($quantityInput.val());

        // 使用Ajax增加数量
        $.ajax({
            type: 'POST',
            url: ajaxurl,
            data: {
                action: 'custom_ajax_add_to_cart',
                product_id: $quantityInput.attr('data-product_id'),
                quantity: currentQuantity + 1
            },
            success: function(response) {
                // 更新购物车小部件数量
                $('.cart-contents-count').text(response);
                $quantityInput.val(currentQuantity + 1);
            }
        });
    });

    // 点击减少数量按钮
    $('.quantity .minus').click(function(e) {
        e.preventDefault();

        var $quantityInput = $(this).next('.qty');
        var currentQuantity = parseInt($quantityInput.val());

        if (currentQuantity > 1) {
            // 使用Ajax减少数量
            $.ajax({
                type: 'POST',
                url: ajaxurl,
                data: {
                    action: 'custom_ajax_add_to_cart',
                    product_id: $quantityInput.attr('data-product_id'),
                    quantity: currentQuantity - 1
                },
                success: function(response) {
                    // 更新购物车小部件数量
                    $('.cart-contents-count').text(response);
                    $quantityInput.val(currentQuantity - 1);
                }
            });
        }
    });
});

<span class="cart-contents-count"><?php echo WC()->cart->get_cart_contents_count(); ?></span>