Provides a way to create a strongly typed reference to the ASP.NET master page when the master page is accessed from the Master property.
Use the @ MasterType directive to set the strong type for the master page, as accessed through the Master property.
if VirtualPath is not defined, the type must exist in one of the currently linked assemblies, such as App_Bin or App_Code.
If both attributes, TypeName and VirtualPath, are defined, the @ MasterType directive will fail.
The following code example demonstrates how to set the virtual path to an ASP.NET master page.
<%@ MasterType VirtualPath="~/masters/SourcePage.master"" %>