WCF 三步曲（中） WCF的客户使用

 WCF的客户端使用

上一篇说的是入门，一个WCF程序是什么样的，这一篇客户端应用如何配置创建和使用WCF服务。

WCF客户端一般应包括以下一些内容

和服务端商量好的contract、endpoint

创建客户端代理

调用服务操作

关闭服务调用资源

 

       如何创建客户端代理

         发布了一个服务以后，可以用ServiceModel Metadata Utility Tool创建客户端代理，如服务地址为为：http://zycblog/Service/Service.svc?wsdl，可以通过以下命令行创建客户端代理

         svcutil /language:vb /out:ClientCode.vb /config:app.config http://zycblog /Service/Service.svc?wsdl

        俱体的操作步骤就不详述了，类似的文章很多。

    一个客户端代理是一个本地对像，通过他可以WCF服务通信，我们可通过Visual Studio来创建代理，方法是在项目里添加Service Reference。完了以后示例如下

 

[System.ServiceModel.ServiceContractAttribute(
  Namespace = "http://microsoft.wcf.documentation"
)]
public interface ISampleService
{
    [System.ServiceModel.OperationContractAttribute(
      Action = "http://microsoft.wcf.documentation/ISampleService/SampleMethod",
      ReplyAction = "http://microsoft.wcf.documentation/ISampleService/SampleMethodResponse"
    )]
    [System.ServiceModel.FaultContractAttribute(
      typeof(microsoft.wcf.documentation.SampleFault),
      Action = "http://microsoft.wcf.documentation/ISampleService/SampleMethodSampleFaultFault"
    )]
    string SampleMethod(string msg);
}

在创建客户端代理时，请注意客户端的配置文件，特别是endpoint,其配置里包含了contract,binding,address.常见的示例 如下 

<configuration>
    <system.serviceModel>
        <bindings>
            <wsHttpBinding>
                <binding name="WSHttpBinding_ISampleService" closeTimeout="00:01:00"
                    openTimeout="00:01:00" receiveTimeout="00:01:00" sendTimeout="00:01:00"
                    bypassProxyOnLocal="false" transactionFlow="false" hostNameComparisonMode="StrongWildcard"
                    maxBufferPoolSize="524288" maxReceivedMessageSize="65536"
                    messageEncoding="Text" textEncoding="utf-8" useDefaultWebProxy="true"
                    allowCookies="false">
                    <readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"
                        maxBytesPerRead="4096" maxNameTableCharCount="16384" />
                    <reliableSession ordered="true" inactivityTimeout="00:10:00"
                        enabled="false" />
                    <security mode="Message">
                        <transport clientCredentialType="None" proxyCredentialType="None"
                            realm="" />
                        <message clientCredentialType="Windows" negotiateServiceCredential="true"
                            algorithmSuite="Default" establishSecurityContext="true" />
                    </security>
                </binding>
            </wsHttpBinding>
        </bindings>
        <client>
            <endpoint address="http://localhost:8080/SampleService" binding="wsHttpBinding"
               bindingConfiguration="WSHttpBinding_ISampleService" contract="ISampleService"
                name="WSHttpBinding_ISampleService">
            </endpoint>
        </client>
    </system.serviceModel>
</configuration>

 

调用操作

当客户端代理创建好，并配置好以后，就可以通过代理来调用WCF服务了，调用完毕需注意关闭调用，

下面用示例来说明，假如 contraact代码如下 

namespace Microsoft.ServiceModel.Samples

{
    using System;
    using System.ServiceModel;
    [ServiceContract(Namespace = http://microsoft.servicemodel.samples/)]
    public interface ICalculator
   {
        [OperationContract]
        double Add(double n1, double n2);
        [OperationContract]
        double Subtract(double n1, double n2);
        [OperationContract]
        double Multiply(double n1, double n2);
        [OperationContract]
        double Divide(double n1, double n2);
    }
}

 

调用代码如下 

CalculatorClient wcfClient = new CalculatorClient();
try
{
    Console.WriteLine(wcfClient.Add(4, 6));
    wcfClient.Close();
}
catch (TimeoutException timeout)
{
    // Handle the timeout exception.
    wcfClient.Abort();
}
catch (CommunicationException commException)
{
    // Handle the communication exception.
    wcfClient.Abort();
}