WCF

1. WCF VS Web Service

Difference between WCF and Web service

Web service is a part of WCF. WCF offers much more flexibility and portability to develop a service when comparing to web service. Still we are having more advantages over Web service, following table provides detailed difference between them.

Features	Web Service	WCF
Hosting	It can be hosted in IIS	It can be hosted in IIS, windows activation service, Self-hosting, Windows service
Programming	[WebService] attribute has to be added to the class	[ServiceContract] attribute has to be added to the class
Model	[WebMethod] attribute represents the method exposed to client	[OperationContract] attribute represents the method exposed to client
Operation	One-way, Request- Response are the different operations supported in web service	One-Way, Request-Response, Duplex are different type of operations supported in WCF
XML	System.Xml.serialization name space is used for serialization	System.Runtime.Serialization namespace is used for serialization
Encoding	XML 1.0, MTOM(Message Transmission Optimization Mechanism), DIME, Custom	XML 1.0, MTOM, Binary, Custom
Transports	Can be accessed through HTTP, TCP, Custom	Can be accessed through HTTP, TCP, Named pipes, MSMQ,P2P, Custom
Protocols	Security	Security, Reliable messaging, Transactions

 2. Bindings 和 Behavior

Binding	Description
BasicHttpBinding	Basic Web service communication. No security by default
WSHttpBinding	Web services with WS-* support. Supports transactions
WSDualHttpBinding	Web services with duplex contract and transaction support
WSFederationHttpBinding	Web services with federated security. Supports transactions
MsmqIntegrationBinding	Communication directly with MSMQ applications. Supports transactions
NetMsmqBinding	Communication between WCF applications by using queuing. Supports transactions
NetNamedPipeBinding	Communication between WCF applications on same computer. Supports duplex contracts and transactions
NetPeerTcpBinding	Communication between computers across peer-to-peer services. Supports duplex contracts
NetTcpBinding	Communication between WCF applications across computers. Supports duplex contracts and transactions

Binding 是和behavior相关，是How的操作；Simple definition for Binding describes how the client will communicate with service。

3. EndPoint

 

4. Tips

• Always create the service with Interface->Implementation format, mention the contract in Interface.
• Define the service in Class library and refer the class library in Host project. Don’t use service class in host project.
• Change the instance mode to per call as default.
• Always catch exception using try/catch block and throw exception using FaultException < T >.
• Logging and Include exception should be enable while compiling the project in debug mode. While in production deployment disable the logging and Include exception details.

5. Contact 和 Service Host

　　1. Mainly there are four types of contracts available in WCF: 

　　　　a. Service Contract

　　　　b. Data Contract

　　　　c. Message Contract

　　　　d. Fault Contract

　　2. Services can be hosted or executed, so that it will be available to everyone accessing from the client. WCF service can be hosted by following mechanism

• • IIS

    Internet information Service provides number of advantages if a Service uses Http as protocol. It does not require Host code to activate the service, it automatically activates service code.

  • Windows Activation Service

    (WAS) is the new process activation mechanism that ships with IIS 7.0. In addition to HTTP based communication, WCF can also use WAS to provide message-based activation over other protocols, such as TCP and named pipes.

  • Self-Hosting

    WCF service can be self hosted as console application, Win Forms or WPF application with graphical UI.

  • Windows Service

    WCF can also be hosted as a Windows Service, so that it is under control of the Service Control Manager (SCM).

6. Message and Channel

　　1. WCF Message --  is the unit of data exchange between client and service. It consists of several parts, including a body and headers.

　　2. WCF Runtime -- WCF runtime is the set of object responsible for sending and receiving message. For example formatting the message, applying security and transmitting and receiving message using various protocol.

　　3. Channels -- Channels are the core abstraction for sending message to and receiving message from an Endpoint. 大致分为以下两种：

　　　　a. Transport Channels -- Handles sending and receiving message from network. Protocols like HTTP, TCP name pipes and MSMQ.

　　　　b. Protocol Channels -- Implements SOAP based protocol by processing and possibly modifying message. e.g. WS-Security and WS-Reliability.

7. WCF Client

　　1. A client application is a managed application that uses a WCF client to communicate with another application.

8. WCF Architecture

　　

9. 

http://www.wcftutorial.net/Contracts-and-Service-Host.aspx