Visual Studio® 2008: Windows®

Communication Foundation

Module 1: Getting Started with Windows Communication Foundation

• Designing an Application to Be Part of a Service Oriented Architecture (SOA)

• Overview of WCF Architecture

• Using a Language-Level Interface As a Service Contract

• Implementing a Simple WCF Service in Visual Studio 2008

• Consuming a Simple WCF Service in Visual Studio 2008

Lesson: Designing an Application to Be Part of a Service Oriented Architecture (SOA)

• Benefits of Service Oriented Architecture

• Designing an SOA Application

• Services, Components, and Objects

• WCF and SOA

• WCF in an SOA Context

Primary objective:

• Deliver more business benefit faster

• Independent services act as building blocks for new or

improved business processes

• Applications become: User interface flows that make use of services Longer-running workflows that make use of services Portals and mash-ups that make use of services

• Success depends more on business practice than technology

• SOA enables you to build services much faster once the

business has made its mind up

Benefits of Service Oriented Architecture

Designing an SOA Application

Get commitment for the effort required

1

Gather the services

2

Group related business functions together

3

Services, Components, and Objects

ComponentsService

Objects

WCF and SOA

WCF supports SOA:

However:

• Developers do not have to learn WSDL

• Functionality is handled by the runtime

• Tools to enable easy creation and consumption of services

• Just because you have exposed an interface over a Web service protocol stack does not mean that you have created part of an SOA

• SOA helps you design services and WCF enables you to implement these services

WCF in an SOA Context

Example:

Language level:

Service level:

• Customer management service application

• Objects for customers persisted into a database

• Business rules (some may be in stored procedures)

• Business interface to embody small amounts of business process

• Standard .NET Framework objects

• Similar business facades but with potentially different data types that are more service friendly

• These are, and use, WCF-aware data types

Lesson: Overview of WCF Architecture

• Service-Oriented Development with WCF

• Sending a WCF Message

• The ABC of Endpoints

• Structure of a Service

• A Unified Programming Model

• Communicating with Non-WCF Services

Service-Oriented Development with WCF

Create a service:

• Over a network protocol

Use a service:

• Contact the service to access one part of that functionality

• Clients and services communicate by passing messages

• Aimed at clients and services that do not share the same address space

• Service-oriented architecture is a concept related to the style of the application and granularity of the services

• Not limited to one particular set of protocols

Sending a WCF Message

Client ServiceWCF

dispatcherProxy

Message EncodingEncoding

Transportchannel

Transportchannel

ChannelChannelChannelChannel

ChannelChannel

Transportchannel

Transportchannel

EncodingEncodingBindingBinding

ChannelChannelChannelChannel

ChannelChannel EndpointsEndpoints

The ABC of Endpoints

Service

Where to find the service

Example: http://localhost:8001/MathService

Where to find the service

Example: http://localhost:8001/MathService

AddressAddress

How to communicate with the service

Example: BasicHttpBinding

How to communicate with the service

Example: BasicHttpBinding

BindingBinding

What the service can do for you

Example: [OperationContract]int Add(int num1, int num2);

What the service can do for you

Example: [OperationContract]int Add(int num1, int num2);

ContractContract

Structure of a Service

Service

.NET Classesand Interface

ServiceHostService Contracts for

Domain Functionalityor Metadata Exchange

A Unified Programming Model

A unified development model

WindowsCommunication

Foundation

Many confusing and complicated options

Remoting COMDCOM

COM+MSMQ

WSEASMX

Communicating With Non-WCF Services

•Web services

Older Web services such as ASP.NET .ASMX files

Other Web service stacks that support different WS-* protocols

Plain Old XML services (POX)

Internal protocols

MSMQ (there are several specific bindings)

.NET Remoting

COM+

Lesson: Using a Language-Level Interface As a Service Contract

• Example of a Simple Contract

• The ServiceContract Attribute

• The OperationContract Attribute

• Data and Messages

• Contracts, Metadata, and Artifacts

Example of a Simple Contract

using System;using System.ServiceModel;

namespace ConnectedWCF{ [ServiceContract(Namespace="http://myuri.org/Simple") ] public interface IBank { [OperationContract] decimal GetBalance(string account);

[OperationContract] void Withdraw(string account, decimal amount);

[OperationContract] void Deposit(string account, decimal amount); }}

using System;using System.ServiceModel;

namespace ConnectedWCF{ [ServiceContract(Namespace="http://myuri.org/Simple") ] public interface IBank { [OperationContract] decimal GetBalance(string account);

[OperationContract] void Withdraw(string account, decimal amount);

[OperationContract] void Deposit(string account, decimal amount); }}

Principal namespace for WCF

Attributes control exposure of types and methods

The ServiceContract Attribute

Service contracts:

The ServiceContract attribute:

Namespace serves to disambiguate types and operations in service metadata:

• Can be used on interfaces or classes

• Is identified by tools and environments designed for WCF

• Support services

• Are analogous to interfaces on a polymorphic object – caller may not care about other contracts

• Are only visible to clients if exported on an endpoint

• Contains one or more operations

• Defaults to http://tempuri.org

• Not to be confused with language-level namespace

The OperationContract Attribute

• Attribute can be used on methods but not other class elements such as properties or indexers

• Identified by tools and environments designed for WCF

• Methods are only visible in service contract if marked with

OperationContract

Data and Messages

• Parameters and return values must be marshaled between client and server

• CLR types are mapped to XML Infoset by serialization

• WCF enables you to define custom serialization

• Serialized data is packed into the message

• Contents and structure of message must be understood by client or service at the other end

• Data and message contracts provide control overthese areas

Contracts, Metadata, and Artifacts

ServiceClass

ServiceInterface

ServiceMetadata

Implements

RunningService

ServiceProxy

Implements

ServiceAssembly

ProxyArtifacts

Generate

Generate

Generate

Generate

Generate

Generate

ServiceModel Metadata Utility Tool (Svcutil.exe) generates metadataand artifacts

ServiceModel Metadata Utility Tool (Svcutil.exe) generates metadataand artifacts

Lesson: Implementing a Simple WCF Service in Visual Studio 2008

• Defining the Service Contract and Service Class

• Hosting the Service

• Configuring the Service

• Demonstration: Creating a Simple Bank Service

Defining the Service Contract and Service Class

Hosting the Service

Configuring the Service

Demonstration: Creating a Simple Bank Service

In this demonstration, you will see how to:

• Create a simple WCF service in Visual Studio 2008

• Host the service in IIS by using the facilities of Visual Studio 2008

Lesson: Consuming a Simple WCF Service in Visual Studio 2008

• Importing the Metadata

• Calling the Service by Using the Proxy

• Demonstration: Calling the Simple Bank Service

Importing the Metadata

Calling the Service by Using the Proxy

Metadata import generates client-side classes that represents the service and service contract:

• <ServiceName> Client is the service proxy type

• <ServiceContractName> is the contract representation type

Client-side class created in the current project’s namespace when you add the service reference

using BankServiceClient.BankServiceReference;...IBank proxy = new BankClient("WSHttpBinding_IBank");...double balance = proxy.GetBalance(1234);

Demonstration: Calling the Simple Bank Service

In this demonstration, you will see how to invoke operations on a simple WCF service by using the facilities of Visual Studio 2008

Lab: Creating a Simple Service

• Exercise 1: Creating a Simple WCF Service

• Exercise 2: Calling the Simple WCF Service

Logon information

Virtual machine 6461A-LON-DEV-01

User name Student

Password Pa$$w0rd

Estimated time: 60 minutes

Lab Review

• What must you do to the ClinicAdminClient application if you change the AppointmentServiceContract?

• What would be the consequences to the solution if you removed the default metadata endpoint from the AppointmentServiceIISHost project?

Module Review and Takeaways

• Review Questions

• Best Practices

• Tools