无法运行第一个WCF服务

这是我的第一个WCF服务，我收到一个错误：

Failed to add a service. Service metadata may not be accessible. Make sure your service is running and exposing metadata.

代码：

Web.Config

    <?xml version="1.0"?>
<configuration>

  <system.web>
    <compilation debug="true" targetFramework="4.0" />
  </system.web>
  <system.serviceModel>
    <services>
      <service name="WcfMathServiceLibrary.MathService">
        <host>
          <baseAddresses>
            <add baseAddress="http://localhost:8732/WcfMathServiceLibrary/MathService/"/>
          </baseAddresses> 
        </host>
        <endpoint address="" binding="wsHttpBinding" contract="WcfMathServiceLibrary.MathService">
          <identity>
            <dns value="localhost" />
          </identity>
        </endpoint>

        <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange" >
        </endpoint>
      </service>
    </services>
    <behaviors>
      <serviceBehaviors>
        <behavior>
          <!-- To avoid disclosing metadata information, set the value below to false and remove the metadata endpoint above before deployment -->
          <serviceMetadata httpGetEnabled="true"/>
          <!-- To receive exception details in faults for debugging purposes, set the value below to true.  Set to false before deployment to avoid disclosing exception information -->
          <serviceDebug includeExceptionDetailInFaults="false"/>
        </behavior>
      </serviceBehaviors>
    </behaviors>
    <serviceHostingEnvironment multipleSiteBindingsEnabled="true" />
  </system.serviceModel>
 <system.webServer>
    <modules runAllManagedModulesForAllRequests="true"/>
  </system.webServer>

</configuration>

---

我不确定是什么问题。你能指导我吗？

我认为你的合同可能需要指向接口，而不是具体的实现

<endpoint address="" binding="wsHttpBinding" contract="WcfMathServiceLibrary.IMath">

---

我不明白你的意思。我需要在地址中添加任何内容吗？不，只需更改合同以指向接口IMath而不是MathService

<endpoint address="" binding="wsHttpBinding" contract="WcfMathServiceLibrary.IMath">