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What Is the Windows Communication
Foundation?
How Does It Work?
How Do I Use and Deploy It?
Bindings
Addresses
Contracts
How to host WCF services in ASP.NET
How WCF works inside of ASP.NET

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Our next-generation platform for distributed systems
A set of extensions to the Microsoft.NET Framework
2.0
Build WCF services in Visual Studiousing any .NET
Language
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Intelligent code editing, IDE Extensions for WCF, debugging, re-factoring, code snippets, etc.
Visual Basic .NET, Visual C#, etc.
Runs on
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Microsoft Windows Vista
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Microsoft Windows XP
Microsoft Windows Server 2003

The Unified Framework For Rapidly Building
Service-Oriented Applications
WCF combines the functionality from ASP.NET
Web Services , .NET Remoting, Message Queuing and
Enterprise Services.
Windows Communication Foundation (WCF) ASP.NET Web Service
WCF supports multiple bindings HTTP, WSHTTP, TCP, MSMQ.
WCF supports Atomic Transactions*.
ASP.NET Web Services supports only HTTP binding.
ASP.NET Web Services does not support Atomic Transactions*.
By default WCF uses SOAP for sending and receiving the messages. But WCF can support any kind of message format not only SOAP.
ASP.NET Web Services can send and receive messages via the SOAP only.
The System.Runtime.Serialization.DataContract and
System.Runtime.Serialization.DataMember attributes of the WCF's
System.Runtime.Serialization assembly can be added for .NET types to indicate that instances of the type are to be serialized into XML, and which particular fields or properties of the type are to be serialized.
ASP.NET Web Services uses XmlSerializer to translate the XML data (Message
Send or received) into .NET objects.

Windows Communication Foundation
• Unifies today’s distributed technologies
• Lets you develop/deploy/manage one model
• Visual Studio.NET integration
• Broad support for Web services
(WS-*) specifications
• Compatible with existing Microsoftdistributed application technologies
• Enables development of loosely-coupled services
• Config-based communication

ASMX
Interop with other platforms
Attribute-
Based
Programming
Enterprise
Services
WS-*
Protocol
Support
WSE
.NET
Remoting
Extensibility
Location transparency
Message-
Oriented
Programming
System.Messaging

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

What Is the Windows Communication
Foundation?
How Does It Work?
How Do I Use and Deploy It?
Bindings
Addresses
Contracts
How to host WCF services in ASP.NET
How WCF works inside of ASP.NET

Endpoints
Client
Endpoint Message
Service
Endpoint
Endpoint

Address, Binding, Contract
Endpoints - All communications with the WCF service will happen via the endpoints.
The endpoint is composed of 3 parts (collectively called as ABC's of endpoint) as defines below:
Address: The endpoints specify a Address that defines where the endpoint is hosted.
Contract: The endpoints specify a Contract that defines which methods of the Service class will be accessible via the endpoint; each endpoint may expose a different set of methods.
Binding: The endpoints also define a binding that specifies how a client will communicate with the service and the address where the endpoint is hosted.Various
components of the WCF are depicted in the figure below.
Client
C B A Message
A B C Service
A B C

Behaviours and Metadata
Metadata
Bv
Bv
Client
C B A
Proxy
Message
A B C
A B C
Service
Bv
Bv
ServiceHost()

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What Is the Windows Communication
Foundation?
How Does It Work?
How Do I Use and Deploy It?
Bindings
Addresses
Contracts
How to host WCF services in ASP.NET
How WCF works inside of ASP.NET

Service
Define
Contract
Client
Generate
Proxy
Implement
Service
Pick
Endpoint
Define
Endpoints
Host
Service

Web Host within IIS:
Self-Host within any .NET process:
• Available for any service
• Console apps, windowed apps, .NET NT Services …

Building a simple service and client

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


What Is the Windows Communication
Foundation?
How Does It Work?
How Do I Use and Deploy It?
Bindings
Addresses
Contracts
How to host WCF services in ASP.NET
How WCF works inside of ASP.NET

You can choose a pre-defined binding:
<endpoint name=“MyService” address=“MyAddress” binding=“netTcpBinding” contract=“IMyInterface”
/>
Binding
BasicHttpBinding
WsHttpBinding
NetTcpBinding
NetNamePipesBinding
NetMSMQBinding
NetPeerTcpBinding
Purpose
Basic Profile 1.1 Interop and Intergration w/ASMX
Basis for WS-* interop
Supports WS-Security, WS-RM, WS-Tx
.NET
 .NET across processes
Secure, reliable duplexed
.NET
 .NET across processes
Secure, reliable duplexed
.NET
 .NET via MSMQ
.NET Peer  Peer

You can customize a pre-defined binding:
<services>
<service name=“MyService”>
<endpoint address=“MyAddress” binding=“wsHttpBinding” bindingConfiguration=“MyReliableBinding” contract=“IMyInterface” />
<service/>
</services>
<bindings>
<wsHttpBinding>
<binding name=“MyReliableBinding”>
<reliableSession enabled=“true” ordered=“true”
</binding>
</wsHttpBinding>
</bindings>

You can define custom bindings:
<services>
<service name=“MyService”>
<endpoint address=“MyAddress” binding=“wsHttpBinding” bindingConfiguration=“MyReliableBinding” contract=“IMyInterface” />
<service/>
</services>
<bindings>
<wsHttpBinding>
<binding name=“MyReliableBinding”>
<reliableSession enabled=“true” ordered=“true”
</binding>
</wsHttpBinding>
</bindings>

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

What Is the Windows Communication
Foundation?
How Does It Work?
How Do I Use and Deploy It?
Bindings
Addresses
Contracts
How to host WCF services in ASP.NET
How WCF works inside of ASP.NET

An endpoint address is relative to a base address:
<services>
<host>
<baseAddresses>
<add baseAddress="http://localhost:8000/MyBaseAddress"/>
</baseAddresses>
</host>
<service name=“MyService”>
<endpoint address=“MyEndpointAddress” binding=“wsHttpBinding” bindingConfiguration=“MyReliableBinding” contract=“IMyInterface” />
<service/>
</services>
For a Web-Hosted service, the base address is that of its virtual directory

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What Is the Windows Communication
Foundation?
How Does It Work?
How Do I Use and Deploy It?
Bindings
Addresses
Contracts
How to host WCF services in ASP.NET
How WCF works inside of ASP.NET

• Service Contract: Describes the operations a service can perform. Maps CLR types to WSDL.
• Data Contract: Describes a data structure.
Maps CLR types to XSD.
• Message Contract: Defines the structure of the message on the wire. Maps CLR types to
SOAP messages.

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What Is the Windows Communication
Foundation?
How Does It Work?
How Do I Use and Deploy It?
Bindings
Addresses
Contracts
How to host WCF services in ASP.NET
How WCF works inside of ASP.NET

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Write your service as usual:
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[ServiceContract]
[OperationContract] etc.
ServiceHost’s are represented as .svc files:
<% @ServiceHost Service=“HelloService” %>
Service attribute is a CLR type name
Matches <service name=“xxx”> from web.config

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Anywhere you can put code in
ASP.NET:
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Inline in the .svc file
In a .cs/.vb in App_Code
In a class library (.dll) located in \bin
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WCF plays nicely with ASP.NET’s dynamic compilation system

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Services can be built in any project type
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Web projects
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Class Libraries
Class libraries have benefits
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Decouples implementation from hosting environment
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Can test services in other hosts (e.g. console apps) during development
However, WCF doesn’t care which project type you use…use what makes sense for you

Hosting WCF in ASP.NET

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


What Is the Windows Communication
Foundation?
How Does It Work?
How Do I Use and Deploy It?
Bindings
Addresses
Contracts
How to host WCF services in ASP.NET
How WCF works inside of ASP.NET

IIS Worker Process
(w3wp.exe)

ASP.NET
w3wp.exe

ASP.NET
Page Framework, UI, Controls,
HTTP Runtime
(System.Web, System.Web.UI)
ASP.NET Managed Hosting Layer
(System.Web.Hosting, System.Web.Compilation) w3wp.exe

ASP.NET
WCF Service Model
Page Framework, UI, Controls,
HTTP Runtime
(System.ServiceModel)
(System.Web, System.Web.UI)
ASP.NET Managed Hosting Layer
(System.Web.Hosting, System.Web.Compilation) w3wp.exe

Service Implementation
Dispatcher
Protocol Channels
HTTP Transport
WCF HttpModule
(grabs *.svc)
Process Host
HTTP
Request
HTTP
Response

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Two technologies, different priorities
WCF: consistency across transports and hosting environments
ASP.NET: optimize for HTTP applications hosted in IIS
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Becomes very important on IIS7/WAS
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WAS == Windows Process Activation
Service

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ASP.NET platform features still work for
ASP.NET
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Forms auth
Session state
File/URL authorization
They just don’t apply to WCF by default









What Is the Windows Communication
Foundation?
How Does It Work?
How Do I Use and Deploy It?
Bindings
Addresses
Contracts
How to host WCF services in ASP.NET
How WCF works inside of ASP.NET