/Windows-Communication-Foundation

Primary LanguageC#

Windows-Communication-Foundation

Overview

  1. Platform for building distributed, service-oriented applications
    1. Define services and hosts for those services
    2. Define clients to connect to services
    3. Secure, Scalable, robust, and flexible
  2. SOAP messaging
  3. WCF Configuration
    1. Endpoints:
      1. Address
      2. Binding
      3. Contract
    2. Behaviors
    3. Bindings
  4. WCF allows you to easily connect clients and services for remote communications.
  5. The service boundary is defined through a combination of the service contract, data contracts, and configuration.
  6. Behaviors configure aspects about how the service behaves when service messages are received
  7. Bindings configure aspects about how the service behaves when sevice messages are received
  8. Binding configure aspects of the communication pipe shared with the client

Implementing Services

  1. Create a WCF Service Library project
  2. Define Service Contract
  3. Define Data Contracts for operation parameters and return types
  4. Define the Service implementation class
  5. Service implementation class can use ServiceBehavior annotation to drive aspects of its behavior when called as a service.
  6. Service instance lifetime:
    1. Per call (favored)
    2. Per session (default)
    3. Singleton

Hosting Services

  1. Services need to run in a host process
  2. The host listens for incoming messages and dispatches calls to the appropriate service method
  3. How the service is exposed by the host is driven through configuration
  4. Hosting Options:
    1. Self Host:
      1. Any .NET process
      2. User ServiceHost class
    2. IIS Host:
      1. can only handle HTTP traffic
      2. When using IIS hosting, there is no need to specify address in endpoint
    3. WCF Service Library
      1. OK for quick "smoke testing"
      2. Generally want to debug and develop with a self host or IIS host

Implementing Clients

  1. To consume WCF services from .NET clients, you need a client proxy
  2. Proxies can be code generated by Visual Studio based on metadata exposed by the service
    1. Service must enable metadata either through WSDL or WS-MetadataExchange endpoint
  3. Proxies can also be hand-coded for more control over the code in the proxy
    1. Encapsulate repeating patterns of usage, leverage WCF extensibility features
  4. Make calls through proxy instance methods
    1. Opens connection to the service
    2. Dispatches the call through SOAP messages
    3. Gets a response message back - completes method
  5. Add Service Reference makes implementing a client proxy simple
  6. Generated proxies have both synchronous and asynchronous methods
  7. Generated client configuration may need to be tweaked to work with service
  8. Manually implemented proxies may make sense to have more control over the proxy implementation

Security

  1. Service calls should be secured
    1. Authentication & Authorization