Windows Communication Foundation(formerly known as Indigo)

AgendaIntroductionWCF ConceptsProgramming WCF

Introduction

What is WCF?Part of the new WinFX platformNew, unified programming model for building connected applications on the Windows platformScale-invariantPay-as-you-go model

What is WCF?Platform for advanced Web Services Standards basedBuilding secure, reliable, transacted solutionsBest choice for implementing SOA applicationsIntegration across platformsClient- or server-side component

What is WCF?Unified Technologies ASMX Web ServicesWeb Service Enhancements, WSE.NET RemotingEnterprise Services, COM+MSMQInteroperability with existing investments

Meta informationHistoryPublicly previewed at PDC 2003Currently in beta 2Due for release in 2006Supported platformsWindows XP SP2Windows Server 2003Windows VistaWindows Server LonghornRequirements.NET Framework 2.0

WCF Concepts

Clients and ServicesClientService

Message

EndpointsThe unit of communicationThe ABC of WCFAddress where to exposeBinding how to exposeContract what to expose Defined in code or in configurationService

Message

Configuration

AddressDefines where a service is locatedSpecifies a URI where the service is locatedRelative or absoluteAddress consist ofSchemeHTTP, TCP, Named pipes, MSMQMachine[Port]PathExamples http://www.mystore.com/StoreFrontnet.tcp://mycomputer:9000/StoreFront

BindingDescribes how a service communicatesSpecifies set of binding elementsTransport; http, tcp, np, msmqEncoding format; text, binary, MTOM, ...Security requirementsReliable session requirementsTransaction requirementsSet of predefined standard bindingsCan be customizedCustom binding

Predefined bindings

Binding Interop Security Session Transactions Duplex basicHttpBinding Basic Profile 1.1TransportNon/an/awsHttpBinding WSMessageYesYesn/awsFederationBinding WS-FederationMessageYesYesYeswsDualHttpBinding WSMessageYesYesYesnetTcpBinding .NETTransportYesYesYesnetNamedPipeBinding .NETTransportYesYesYesnetMsmqBinding .NETTransportYesYesNonetPeerTcpBinding PeerTransportNoNoYesmsmqIntegrationBinding MSMQTransportNoYesNo

Configuration

ContractDefines what a service communicateSupports contract first or code first modelsContract first = interfacesMay use WSDL first as wellMessage vs. RPC style APIsService contractData contract

Service ContractsDescribes what a service doesMaps CLR types to WSDL[ServiceContract] defines the service contract[OperationContract] specifies operationsOne-way, request-reply, duplex MEPs, Sessions, Faults

A Service Contract

Data ContractDefines data structuresMaps CLR types to XML Schema[DataContract] specifies types[DataMember] specifies members Can be applied to private fields!

A Data Contract

BehaviorModifies or extends service or client runtime behavior ExamplesInstancing; Singleton, PrivateSession, SharedSession, PerCall Concurrency; Multiple, Reentrant, Single Throttling; connections, threadingMetadata customizationTransactions; AutoEnlist, Isolation, AutoComplete

Features SummaryAddress

Binding

Behavior

Contract

HTTP TransportTCPTransportNamedPipe TransportMSMQ TransportCustom TransportWS-Security ProtocolWS-RM ProtocolWS-Coord ProtocolDuplex ChannelCustom Protocolhttp://...net.tcp://...net.pipe://...net.msmq://...xxx://...ThrottlingBehaviorMetadata BehaviorError BehaviorCustom BehaviorInstancing BehaviorConcurrency BehaviorTransaction BehaviorSecurity BehaviorRequest/ ResponseOne-WayDuplexnet.p2p://...PeerTransportExternally visible, per-endpointOpaque, per-service,endpoint, or operation

RuntimeFormats, sends and receives messagesDispatches message to service operationAttributes, code and config are used to dynamically create a ServiceHost instancePrecedence: attribute, code, config

HostingASP.NET, .SVC format ()IIS 6: HTTP transport onlyIIS 7: All transportsWindows Activation Service, WASSame process management, health, and activation features as IIS without requiring a Web server.Self hosted, ServiceHostHosted in any CLR appDomainAll transportsIIS/WAS is the expected hosting model

MetadataExposed through WS-MetadataExchange EndpointsEnabled by default, can be disabled through behaviorConsumed using svcutil.exeGenerates code and configuration

DiagnosticsLoggingRequest and reply messagesTracingEnd-to-end trace of [correlated] eventsWMI eventsPerformance monitor countersEvent Log

Programming WCF

Building a WCF applicationApplication DesignServiceDefine ContractsImplement ContractsDefine EndpointsHost & Run ServiceClientGenerate Proxy from MetadataImplement & Run Client

Application Design

Application DesignOrder ServiceAdmin ClientOrder Client

Define ContractsService ContractsOrder client and admin API (duplex)

Data ContractsShopping cartItem

Implementing ContractsOne class per service interfaceClass may specify ServiceBehavior attributes

Defining EndpointsOne per service interfacewsHttpBinding, wsHttpDualBindingRember WCF ABC!Can be specified in code or configurationConfiguration is to be preferred

Endpoint Configuration

HostingSelf hosted in console applicationOne ServiceHost per ServiceType

Generating ProxiesGenerated dynamically from servicesvcutil.exe Note: service must be runningGenerate proxy and configuration filessvcutil http://localhost:8000/StoreFront /out:proxy.cs /config:app.configProxy generator add-in for Visual Studio

Implementing the ClientClient configuration obtained from generated codeStatless server callsRemember to close proxy correctly

Implementing the Admin ClientAgain, client configuration obtained from generated codeDuplex callback interface implementationRequires stateful connection!

Summary

Mappings to SOABoundaries are ExplicitService and data contractsServices are autonomousIndependent deployment, versioning, and securityShare Schema, not ClassIntegration based on message formats and exchange patterns, not classes and objectsPolicy-based compatibilityService compatibility based on policy assertions (behaviors)

SummaryWCF is the next generation Web Services from MicrosoftLearn your ABCDefine contracts firstSupports building SOABut not limited to only thatUnified programming model

ReferencesWCF Official Web Sitehttp://windowscommunication.net/Default.aspx?tabindex=0&tabid=1WCF on MSDNhttp://msdn.microsoft.com/webservices/indigo/default.aspx