What is the .NET version of the PollingDuplexBindingElement?

What is the .NET version of Silverlight's开发者_运维百科 PollingDuplexBindingElement?

I think CompositeDuplexBindingElement is what you are looking for.

It depends on which binding you're using. If you use the TCP or named pipes transport, you don't really need any binding element to support duplex contracts - they're inherently duplex. If you're using HTTP, which is inherently a request/reply protocol, then you need some other binding element like the CompositeDuplexBindingElement as suggested by @vcsjones.