input: [Category] Operations [Description] The WCF provide duplex proxy DuplexClientBase is object-based and is thus not type safe. In addition, the context class InstanceContext is also object based. The compiler does not verify the relationship between these objects, and there is no verification of the relationship between the callback contract type and the service contract. However, you can fix most of these using generics. The solution contains IDesign InstanceContext and DuplexClientBase which provide the added degree of type safety, as well as a matching duplex factory called DuplexChannelFactory. [Last Updated] 9/7/2006 [Title] 
output: Type-Safe Duplex Callbacks