Expression Syntax: <%$ ... %> New in 2.0
ASP.NET 2.0 adds a new declarative expression syntax for substituting values into a page before the page is parsed. This is useful for substituting connection string values or application settings defined in a Web.config file for server control property values. It can also be used to substitute values from a resource file for locaization. More on connection string and resources expressions and expression handlers can be found in the Performing Data Access, Internationalizing Your Application and Extending ASP.NET sections.
<asp:SqlDataSource ID="SqlDataSource1" ConnectionString='<%$ connectionStrings:Pubs %>'
runat="server" SelectCommand="sp_GetAuthors" /> <asp:Label ID="Label1" Text='<%$ Resources: ExchRate, ConvertLabel %>' runat="server"/>
