ASP.NET Web Forms Extensibility: URL Mapping
A long time before ASP.NET Routing came along, ASP.NET already offered a similar functionality: it was called URL mapping.
URL mapping allows having virtual URLs that redirect to real ones. For example, you can have all requests for “/Product/IPhone” redirected to “/Product.aspx?ID=10”. This allows two simple things:
Hiding complexity (the ID parameter, for example);
Hiding the technology in use (in this case, the .ASPX extension is never seen);
Redirecting from one page (such as Default.aspx) to another transparently.
You can configure URL mapping by just adding entries to the urlMapping section on Web.config:
1: <urlMappings enabled="true">
2: <add url="~/Product/IPhone" mappedUrl="~/Product.aspx?ID=10"/>
And that’s it, no modules or additional configuration.
You can keep using the QueryString collection:
1: Int32 id = Convert.ToInt32(this.Request.QueryString["ID"]); //10
2: String path = this.Request.Path; //Product.aspx
The Url property also contains the real URL, but the RawUrl contains the requested URL:
1: String requestedPath = this.Request.RawUrl; //Product/IPhone
2: String mappedPath = this.Request.Url; //http://localhost/Product.aspx?ID=1
So, as you can see, this is much simpler that ASP.NET Routing and should only be used in very simple scenarios: when you are using a version of ASP.NET prior to 3.5, or you want to configure routes only through the Web.config file.