WCF学习笔记（4） 重载

本节内容：1.什么是重载？2.WCF服务端处理重载。3.WCF客户端处理重载。4.源码下载。

一、什么是重载？

  重载指的是在同一个类，接口或结构中包含多个同名的方法，而这些方法的参数列表或返回值不同。正常的做法如下所示：

        public string Say(string lastName)
        {  
            return "Hello " + lastName;
        }

        public string Say(string firstName, string lastName)
        {
             return "Hello " + firstName + "" + lastName;
        }

在WCF中的重载是否不一样呢？

二、WCF服务端的处理重载。

 在WCF中需要为服务操作指定唯一名称，需要用到：OperationContract的Name属性如下所示，如果去掉Name属性，会有异常，可以自己动手实验一下。

契约：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.ServiceModel;
namespace y.WcfServiceContract.OverloadHost.Services
{
    [ServiceContract]
    public interface IHello
    {
        [OperationContract(Name="SayLastName")]
        string Say(string lastName);

        [OperationContract(Name = "SayFullName")]
        string Say(string firstName, string lastName);
    }
}

服务类：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.ServiceModel;
namespace y.WcfServiceContract.OverloadHost.Services
{
    [ServiceBehavior]
    public class HelloService:IHello
    {
        [OperationBehavior]
        public string Say(string lastName)
        {
            Console.WriteLine("Riceive  from client :{0}", lastName);
            return "Hello " + lastName;
        }

        [OperationBehavior]
        public string Say(string firstName, string lastName)
        {
            Console.WriteLine("Riceive from client:{0},{1}", firstName, lastName);
            return "Hello " + firstName + "" + lastName;
        }
    }
}

允许客户端以元数据的形式的获取代理类，对其配置文件如下：

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <system.serviceModel>
    <behaviors>
      <serviceBehaviors>
        <behavior name="metadataBehavior">
          <serviceMetadata />
        </behavior>
      </serviceBehaviors>
    </behaviors>
    <services>
      <service name="y.WcfServiceContract.OverloadHost.Services.HelloService" behaviorConfiguration="metadataBehavior">
        <host>
          <baseAddresses>
            <add baseAddress="net.tcp://localHost:6666/"/>
          </baseAddresses>
        </host>
        <endpoint address="Hello"
                   binding="netTcpBinding"
                   contract="y.WcfServiceContract.OverloadHost.Services.IHello"></endpoint>
        <endpoint address="MEX"
                   binding="mexTcpBinding"
                   contract="IMetadataExchange"></endpoint>
      </service>
    </services>
  </system.serviceModel>
</configuration>

三、WCF客户端处理重载

以两种方式创建代理类看看重载的不同：

1.以元数据方式获取的代理类,产生的Contract 和ClientProxy代码如下：

契约：

    [System.CodeDom.Compiler.GeneratedCodeAttribute("System.ServiceModel", "3.0.0.0")]
    [System.ServiceModel.ServiceContractAttribute(ConfigurationName="MetadataProxys.IHello")]
    public interface IHello {
        
        [System.ServiceModel.OperationContractAttribute(Action="http://tempuri.org/IHello/SayLastName", ReplyAction="http://tempuri.org/IHello/SayLastNameResponse")]
        string SayLastName(string lastName);
        
        [System.ServiceModel.OperationContractAttribute(Action="http://tempuri.org/IHello/SayFullName", ReplyAction="http://tempuri.org/IHello/SayFullNameResponse")]
        string SayFullName(string firstName, string lastName);
    }

ClientProxy:

[System.Diagnostics.DebuggerStepThroughAttribute()]
    [System.CodeDom.Compiler.GeneratedCodeAttribute("System.ServiceModel", "3.0.0.0")]
    public partial class HelloClient : System.ServiceModel.ClientBase<y.WcfServiceContract.OverloadWinClient.MetadataProxys.IHello>, y.WcfServiceContract.OverloadWinClient.MetadataProxys.IHello {
        
        public HelloClient() {
        }
        
        public HelloClient(string endpointConfigurationName) : 
                base(endpointConfigurationName) {
        }
        
        public HelloClient(string endpointConfigurationName, string remoteAddress) : 
                base(endpointConfigurationName, remoteAddress) {
        }
        
        public HelloClient(string endpointConfigurationName, System.ServiceModel.EndpointAddress remoteAddress) : 
                base(endpointConfigurationName, remoteAddress) {
        }
        
        public HelloClient(System.ServiceModel.Channels.Binding binding, System.ServiceModel.EndpointAddress remoteAddress) : 
                base(binding, remoteAddress) {
        }
        
        public string SayLastName(string lastName) {
            return base.Channel.SayLastName(lastName);
        }
        
        public string SayFullName(string firstName, string lastName) {
            return base.Channel.SayFullName(firstName, lastName);
        }
    }

比较WCF服务端的契约可以看出。现在的代理类方法名称均为，WCF服务中OperationContract指定的Name名称。

2.手动编写代理类，实现重载。

契约，和服务端相同，包括OpertaionContract的Name属性，如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.ServiceModel;
namespace y.WcfServiceContract.OverloadWinClient.ManualProxy
{
    [ServiceContract]
    public interface IHello
    {
        [OperationContract(Name = "SayLastName")]
        string Say(string lastName);

        [OperationContract(Name = "SayFullName")]
        string Say(string firstName, string lastName);
    }
}

代理类的实现：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using System.ServiceModel;
using System.ServiceModel.Channels;
namespace y.WcfServiceContract.OverloadWinClient.ManualProxy
{
    public class HelloProxy:ClientBase<IHello>,IHello
    {
        public HelloProxy(string endpointCon)
            : base(endpointCon)
        {
        }

        public string Say(string lastName)
        {
            return base.Channel.Say(lastName);
        }

        public string Say(string firstName, string lastName)
        {
            return base.Channel.Say(firstName, lastName);
        }
    }
}

运行服务端，客户端获取的结果如下，说明通信正常。

四、源码这里下载