ASP.NET Datalist calculate field - asp.net

Question

I recently decided to implement tax on an ecommerce website I've built for fun more than anything and I've hit a stumbling block.
My implementation works well, tax is applied correctly etc, however a buddy pointed out to me today that prices on product pages are normally displayed inc tax.
I was thinking, rather than editing the Business and Data tier, I could change this on the DataList itself but I can't for the life of me work out how I'd actually do that. I've had a look in some text books and had a search around online but because I don't actually know what I'm looking for, I'm stuck :(.
Datalist:
<asp:DataList ID="list" runat="server" RepeatColumns="2" CssClass="ProductList" RepeatDirection="Horizontal"
Width="542px" EnableViewState="False" onitemcommand="list_ItemCommand">
<ItemTemplate>
<div style="width:271px;">
<h3 class="ProductName"><%# HttpUtility.HtmlEncode(Eval("Name").ToString()) %></h3>
<img width="100" border="0" src="<%# Link.ToProductImage(Eval("Thumbnail").ToString()) %>" alt='<%# HttpUtility.HtmlEncode(Eval("Name").ToString()) %>' />
<%# HttpUtility.HtmlEncode(Eval("Description").ToString()) %>
<p>
<b>Price:</b>
<%# Eval("Price", "{0:c}") %>
</p>
<p>
<asp:Button ID="addToCartButton" runat="server" Text="Add to Basket" CommandArgument='<%# Eval("ProductID") %>' CssClass="SmallButtonText" />
</p>
</div>
</ItemTemplate>
</asp:DataList>
Code behind:
// Retrieve the list of products in a Sub Category
list.DataSource = CatalogAccess.GetProductsInSubCategory(subCategoryId, page, out howManyPages);
list.DataBind();
E.g. if the price in the DB is £5, I'd need it to be displayed in the datalist above as £6 which includes the current UK VAT rate of 20%.
So:
DBPrice * 1.2 = IncVatPrice
I hope this makes sense!
Thanks in advance,
Matt

Answer 1

Instead of
<%# Eval("Price", "{0:c}") %>
use an expression somewhat similar to
<%# String.Format("{0:c}", (Decimal)Eval("Price")*1.2) %>
Or implement a function in codebehind:
protected string IncludeVat(object dataItem)
{
Decimal price = (Decimal)DataBinder.Eval(dataItem, "Price");
return String.Format("{0:c}", price * 1.2);
}
and call it in your DataList like that
<%# IncludeVat(Container.DataItem) %>
http://www.pluralsight-training.net/community/blogs/fritz/archive/2005/12/16/17507.aspx