C# 4 and .NET 4

outing ❘ 1249
If you have two routes that map to the same URL, you may want to determine which route was matched. To
do so, you can include additional data that is passed to the page as a data token. Data tokens are supplied
with another RouteValueDictionary collection, containing a collection of name/value pairs of route
parameters and data tokens. For example:
RouteTable.Routes.Add("RouteName",
new Route("path/{pathparameter}",
new RouteValueDictionary
{
{ "pathparameter", "yes" }
},
new RouteValueDictionary
{
{ "pathparameter", "yes|no" }
},
new RouteValueDictionary
{
{ "customdatatoken", "yesnomatch" }
},
new PageRouteHandler("~/target.aspx")));
If this route is matched a data token called customdatatoken with a string value of yesnomatch is passed
to the target URL, so that pages can identify that this route was used.
You can pass whatever data you like as a data token for a parameter, so this is only one example of how you
might use it.
using route Parameters
Reading and using parameter values that are passed to pages through ASP.NET routing is very similar
to doing the same for query string parameters. Instead of using Request.QueryString, you use Page
.RouteData, which is populated by ASP.NET when your page is loaded. This contains all of the
information you need to extract route parameters or data tokens.
Parameter values are also available for use in ASP.NET markup, through expression builders and data query
parameter values.
routeData Values
The route parameters are available in code through the Page.RouteData.Values property, which is
another instance of the RouteValueDictionary class. Similarly, data tokens are available through Page
.RouteData.DataTokens. In the example web site, values are extracted from the Values property and
displayed through a DataGrid with the following code:
if (Page.RouteData.Values.Count == 0)
{
this.NoRoutingLabel.Text = "None.";
}
else
{
GridView2.DataSource = from entry in Page.RouteData.Values
select
new
{
Name = entry.Key,
Value = entry.Value
};
GridView2.DataBind();
}
code snippet PCSRoutingDemo/MasterPage.master.cs
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