前面为大家介绍过WCF的特点，现在再讲解一下WCF基础概念。
在WCF里，各个Application之间的通信是由EndPoint来实现的，EndPoint是WCF实现通信的核心要素。一个WCF Service可由多个EndPoint集合组成，每个EndPoint只能有一种绑定，就是说EndPoint就是通信的入口，客户端和服务端通过 EndPoint交换信息。
<
service
name
= " "
>
< endpoint address = "" binding = " wsHttpBinding " contract = " myNamespace.IService " >
</ endpoint >
</ service >
< endpoint address = "" binding = " wsHttpBinding " contract = " myNamespace.IService " >
</ endpoint >
</ service >
Endpoint由三部分组成：(A) Address 地址，(B)Binding 绑定，(C)Contract 契约。
- A（Address）: 通过一个URI唯一地标识一个Endpoint，并告诉WCF service的调用者如何找到这个Endpoint。
- B（Binding）： 定义了与数据传输相关的传输协议，消息编码，通信模式，可靠性，安全性，事务，互操作性等信息。Framewrok3.5里已经包括以下几种绑定：
- C（Contract）：它是有关服务响应的操作及进出消息的格式的语法描述，系统就是通过Contract实现操作的。
下面为大家讲解一下Hello World的开发例子。
服务器端：
using
System;
using System.ServiceModel;
namespace myNamespace
{
// 在服务器端定义在一个服务契约
[ServiceContract(Namespace = " myNamespace " )]
public interface IService
{
[OperationContract]
String HelloWorld();
}
// 实现契约
public class MyService:IService
{
public String HelloWorld( string name)
{
return " Hello World " + Name;
}
}
}
using System.ServiceModel;
namespace myNamespace
{
// 在服务器端定义在一个服务契约
[ServiceContract(Namespace = " myNamespace " )]
public interface IService
{
[OperationContract]
String HelloWorld();
}
// 实现契约
public class MyService:IService
{
public String HelloWorld( string name)
{
return " Hello World " + Name;
}
}
}
最后，服务既可以在代码中实现，也可以在配置文件中实现：
<
services
>
< service behaviorConfiguration ="ServiceBehavior" name ="Service" >
//行为可以影响运行是操作的WCF类，它不公在客户端和服务器启动WCF运行时被执行，还可以在二者之间流动消息时被执行。
< endpoint address ="" binding ="wsHttpBinding" contract ="IService" >
< identity >
< dns value ="localhost" />
</ identity >
</ endpoint >
< endpoint address ="mex" binding ="mexHttpBinding" contract ="IMetadataExchange" />
//mexHttpBinding定义了WCF的元数据。当没有定义元数据时，服务依然能够执行，但不能在HTTP中被发现。
</ service >
</ services >
< behaviors >
< serviceBehaviors >
< behavior name ="ServiceBehavior" >
< serviceMetadata httpGetEnabled ="true" />
< serviceDebug includeExceptionDetailInFaults ="true" />
</ behavior >
</ serviceBehaviors >
</ behaviors >
< service behaviorConfiguration ="ServiceBehavior" name ="Service" >
//行为可以影响运行是操作的WCF类，它不公在客户端和服务器启动WCF运行时被执行，还可以在二者之间流动消息时被执行。
< endpoint address ="" binding ="wsHttpBinding" contract ="IService" >
< identity >
< dns value ="localhost" />
</ identity >
</ endpoint >
< endpoint address ="mex" binding ="mexHttpBinding" contract ="IMetadataExchange" />
//mexHttpBinding定义了WCF的元数据。当没有定义元数据时，服务依然能够执行，但不能在HTTP中被发现。
</ service >
</ services >
< behaviors >
< serviceBehaviors >
< behavior name ="ServiceBehavior" >
< serviceMetadata httpGetEnabled ="true" />
< serviceDebug includeExceptionDetailInFaults ="true" />
</ behavior >
</ serviceBehaviors >
</ behaviors >
客户端:
通过Add Service Reference引用服务地址：
添加配置文件：
<
system.serviceModel
>
< bindings >
< basicHttpBinding >
< binding name ="wsHttpBinding_IService" closeTimeout ="00:01:00"
openTimeout ="00:01:00" receiveTimeout ="00:10:00" sendTimeout ="00:01:00"
allowCookies ="false" bypassProxyOnLocal ="false" hostNameComparisonMode ="StrongWildcard"
maxBufferSize ="65536" maxBufferPoolSize ="524288" maxReceivedMessageSize ="65536"
messageEncoding ="Text" textEncoding ="utf-8" transferMode ="Buffered" useDefaultWebProxy ="true" >
< readerQuotas maxDepth ="32" maxStringContentLength ="8192" maxArrayLength ="16384"
maxBytesPerRead ="4096" maxNameTableCharCount ="16384" />
< security mode ="None" >
< transport clientCredentialType ="None" proxyCredentialType ="None" realm ="" />
< message clientCredentialType ="UserName" algorithmSuite ="Default" />
</ security >
</ binding >
</ basicHttpBinding >
</ bindings >
< client >
< endpoint address ="http://localhost/myNamespace.IService.svc" binding ="wsHttpBinding"
bindingConfiguration ="wsHttpBinding_IService"
contract ="myNamespace.IService" name ="wsHttpBinding_IService" />
</ client >
</ system.serviceModel >
< bindings >
< basicHttpBinding >
< binding name ="wsHttpBinding_IService" closeTimeout ="00:01:00"
openTimeout ="00:01:00" receiveTimeout ="00:10:00" sendTimeout ="00:01:00"
allowCookies ="false" bypassProxyOnLocal ="false" hostNameComparisonMode ="StrongWildcard"
maxBufferSize ="65536" maxBufferPoolSize ="524288" maxReceivedMessageSize ="65536"
messageEncoding ="Text" textEncoding ="utf-8" transferMode ="Buffered" useDefaultWebProxy ="true" >
< readerQuotas maxDepth ="32" maxStringContentLength ="8192" maxArrayLength ="16384"
maxBytesPerRead ="4096" maxNameTableCharCount ="16384" />
< security mode ="None" >
< transport clientCredentialType ="None" proxyCredentialType ="None" realm ="" />
< message clientCredentialType ="UserName" algorithmSuite ="Default" />
</ security >
</ binding >
</ basicHttpBinding >
</ bindings >
< client >
< endpoint address ="http://localhost/myNamespace.IService.svc" binding ="wsHttpBinding"
bindingConfiguration ="wsHttpBinding_IService"
contract ="myNamespace.IService" name ="wsHttpBinding_IService" />
</ client >
</ system.serviceModel >
最后通过代理直接调用：
static
void
Main(
string
[] args)
{
ServiceClient client = new ServiceClient();
string data = client.HelloWorld( " Leslie " );
Console.Writeline(data);
Console.Read();
}
{
ServiceClient client = new ServiceClient();
string data = client.HelloWorld( " Leslie " );
Console.Writeline(data);
Console.Read();
}
朋友，恭喜你，一个最简单Hello World的WCF已经实现。
然而，如果你要开发一个SOA系统，你不可能将每一个类都编写成一个*.svc文件，那应该怎么做才能真正实现SOA?
下一章将为你详细介绍如何使用WCF实现真正的SOA。
