C# Discount.GetDiscountAmount方法代码示例

        public void Can_calculate_discount_amount_percentage()
        {
            var discount = new Discount()
            {
                UsePercentage = true,
                DiscountPercentage= 30
            };

            discount.GetDiscountAmount(100).ShouldEqual(30);

            discount.DiscountPercentage = 60;
            discount.GetDiscountAmount(200).ShouldEqual(120);
        }

        public void Can_calculate_discount_amount_fixed()
        {
            var discount = new Discount()
            {
                UsePercentage = false,
                DiscountAmount = 10
            };

            discount.GetDiscountAmount(100).ShouldEqual(10);

            discount.DiscountAmount = 20;
            discount.GetDiscountAmount(200).ShouldEqual(20);
        }

        public void Maximum_discount_amount_is_used()
        {
            var discount = new Discount
            {
                UsePercentage = true,
                DiscountPercentage = 30,
                MaximumDiscountAmount = 3.4M
            };

            discount.GetDiscountAmount(100).ShouldEqual(3.4M);

            discount.DiscountPercentage = 60;
            discount.GetDiscountAmount(200).ShouldEqual(3.4M);
            discount.GetDiscountAmount(100).ShouldEqual(3.4M);

            discount.DiscountPercentage = 1;
            discount.GetDiscountAmount(200).ShouldEqual(2);
        }

        /// <summary>
        /// Gets discount amount
        /// </summary>
        /// <param name="productVariant">Product variant</param>
        /// <param name="customer">The customer</param>
        /// <param name="additionalCharge">Additional charge</param>
        /// <param name="quantity">Product quantity</param>
        /// <param name="appliedDiscount">Applied discount</param>
        /// <returns>Discount amount</returns>
        public virtual decimal GetDiscountAmount(ProductVariant productVariant,
            Customer customer,
            decimal additionalCharge,
            int quantity,
            out Discount appliedDiscount)
        {
            appliedDiscount = null;
            decimal appliedDiscountAmount = decimal.Zero;

            //we don't apply discounts to products with price entered by a customer
            if (productVariant.CustomerEntersPrice)
                return appliedDiscountAmount;

            appliedDiscount = GetPreferredDiscount(productVariant, customer, additionalCharge, quantity);
            if (appliedDiscount != null)
            {
                decimal finalPriceWithoutDiscount = GetFinalPrice(productVariant, customer, additionalCharge, false, quantity);
                appliedDiscountAmount = appliedDiscount.GetDiscountAmount(finalPriceWithoutDiscount);
            }

            return appliedDiscountAmount;
        }

        /// <summary>
        /// Gets an order discount (applied to order total)
        /// </summary>
        /// <param name="customer">Customer</param>
        /// <param name="orderTotal">Order total</param>
        /// <param name="appliedDiscount">Applied discount</param>
        /// <returns>Order discount</returns>
        protected virtual decimal GetOrderTotalDiscount(Customer customer, decimal orderTotal, out Discount appliedDiscount)
        {
            appliedDiscount = null;
            decimal discountAmount = decimal.Zero;
            if (_catalogSettings.IgnoreDiscounts)
                return discountAmount;

            var allDiscounts = _discountService.GetAllDiscounts(DiscountType.AssignedToOrderTotal);
            var allowedDiscounts = new List<Discount>();
            if (allDiscounts != null)
                foreach (var discount in allDiscounts)
                    if (_discountService.IsDiscountValid(discount, customer) &&
                               discount.DiscountType == DiscountType.AssignedToOrderTotal &&
                               !allowedDiscounts.ContainsDiscount(discount))
                        allowedDiscounts.Add(discount);

            appliedDiscount = allowedDiscounts.GetPreferredDiscount(orderTotal);
            if (appliedDiscount != null)
                discountAmount = appliedDiscount.GetDiscountAmount(orderTotal);

            if (discountAmount < decimal.Zero)
                discountAmount = decimal.Zero;

            if (_shoppingCartSettings.RoundPricesDuringCalculation)
                discountAmount = Math.Round(discountAmount, 2);

            return discountAmount;
        }

        /// <summary>
        /// Gets discount amount
        /// </summary>
        /// <param name="product">Product</param>
        /// <param name="customer">The customer</param>
        /// <param name="productPriceWithoutDiscount">Already calculated product price without discount</param>
        /// <param name="appliedDiscount">Applied discount</param>
        /// <returns>Discount amount</returns>
        protected virtual decimal GetDiscountAmount(Product product,
            Customer customer,
            decimal productPriceWithoutDiscount,
            out Discount appliedDiscount)
        {
            if (product == null)
                throw new ArgumentNullException("product");

            appliedDiscount = null;
            decimal appliedDiscountAmount = decimal.Zero;

            //we don't apply discounts to products with price entered by a customer
            if (product.CustomerEntersPrice)
                return appliedDiscountAmount;

            //discounts are disabled
            if (_catalogSettings.IgnoreDiscounts)
                return appliedDiscountAmount;

            var allowedDiscounts = GetAllowedDiscounts(product, customer);

            //no discounts
            if (allowedDiscounts.Count == 0)
                return appliedDiscountAmount;

            appliedDiscount = allowedDiscounts.GetPreferredDiscount(productPriceWithoutDiscount);

            if (appliedDiscount != null)
                appliedDiscountAmount = appliedDiscount.GetDiscountAmount(productPriceWithoutDiscount);

            return appliedDiscountAmount;
        }

        /// <summary>
        /// Gets discount amount
        /// </summary>
        /// <param name="product">Product</param>
        /// <param name="customer">The customer</param>
        /// <param name="additionalCharge">Additional charge</param>
        /// <param name="quantity">Product quantity</param>
        /// <param name="appliedDiscount">Applied discount</param>
        /// <returns>Discount amount</returns>
        public virtual decimal GetDiscountAmount(Product product,
            Customer customer,
            decimal additionalCharge,
            int quantity,
            out Discount appliedDiscount)
        {
            if (product == null)
                throw new ArgumentNullException("product");

            appliedDiscount = null;
            decimal appliedDiscountAmount = decimal.Zero;

            //we don't apply discounts to products with price entered by a customer
            if (product.CustomerEntersPrice)
                return appliedDiscountAmount;

            //discount are disabled
            if (_catalogSettings.IgnoreDiscounts)
                return appliedDiscountAmount;

            var allowedDiscounts = GetAllowedDiscounts(product, customer);

            //no discounts
            if (allowedDiscounts.Count == 0)
                return appliedDiscountAmount;

            decimal finalPriceWithoutDiscount = GetFinalPrice(product, customer, additionalCharge, false, quantity);
            appliedDiscount = allowedDiscounts.GetPreferredDiscount(finalPriceWithoutDiscount);

            if (appliedDiscount != null)
                appliedDiscountAmount = appliedDiscount.GetDiscountAmount(finalPriceWithoutDiscount);

            return appliedDiscountAmount;
        }

        /// <summary>
        /// Gets a shipping discount
        /// </summary>
        /// <param name="customer">Customer</param>
        /// <param name="shippingTotal">Shipping total</param>
        /// <param name="appliedDiscount">Applied discount</param>
        /// <returns>Shipping discount</returns>
        protected virtual decimal GetShippingDiscount(Customer customer, decimal shippingTotal, out Discount appliedDiscount)
        {
            appliedDiscount = null;
            decimal shippingDiscountAmount = decimal.Zero;
            if (_catalogSettings.IgnoreDiscounts)
                return shippingDiscountAmount;

            var allDiscounts = _discountService.GetAllDiscounts(DiscountType.AssignedToShipping);
            var allowedDiscounts = new List<Discount>();
            if (allDiscounts != null)
                foreach (var discount in allDiscounts)
                    if (_discountService.ValidateDiscount(discount, customer).IsValid &&
                               discount.DiscountType == DiscountType.AssignedToShipping &&
                               !allowedDiscounts.ContainsDiscount(discount))
                        allowedDiscounts.Add(discount);

            appliedDiscount = allowedDiscounts.GetPreferredDiscount(shippingTotal);
            if (appliedDiscount != null)
            {
                shippingDiscountAmount = appliedDiscount.GetDiscountAmount(shippingTotal);
            }

            if (shippingDiscountAmount < decimal.Zero)
                shippingDiscountAmount = decimal.Zero;

            if (_shoppingCartSettings.RoundPricesDuringCalculation)
                shippingDiscountAmount = RoundingHelper.RoundPrice(shippingDiscountAmount);

            return shippingDiscountAmount;
        }

        /// <summary>
        /// Gets an order discount (applied to order subtotal)
        /// </summary>
        /// <param name="customer">Customer</param>
        /// <param name="orderSubTotal">Order subtotal</param>
        /// <param name="appliedDiscount">Applied discount</param>
        /// <returns>Order discount</returns>
        protected virtual decimal GetOrderSubtotalDiscount(Customer customer,
            decimal orderSubTotal, out Discount appliedDiscount)
        {
            appliedDiscount = null;
            decimal discountAmount = decimal.Zero;
            if (_catalogSettings.IgnoreDiscounts)
                return discountAmount;

            var allDiscounts = _discountService.GetAllDiscounts(DiscountType.AssignedToOrderSubTotal);
            var allowedDiscounts = new List<Discount>();
            if (allDiscounts != null)
                foreach (var discount in allDiscounts)
                    if (_discountService.ValidateDiscount(discount, customer).IsValid &&
                               discount.DiscountType == DiscountType.AssignedToOrderSubTotal &&
                               !allowedDiscounts.ContainsDiscount(discount))
                        allowedDiscounts.Add(discount);

            appliedDiscount = allowedDiscounts.GetPreferredDiscount(orderSubTotal);
            if (appliedDiscount != null)
                discountAmount = appliedDiscount.GetDiscountAmount(orderSubTotal);

            if (discountAmount < decimal.Zero)
                discountAmount = decimal.Zero;

            return discountAmount;
        }