问WCF服务主机找不到任何服务元数据

EN

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.Text;

namespace wcfLib
{            
    [ServiceContract]
    public interface IfaceService
    {
        [OperationContract]
        int wordLen(string word);
    }

    public class StockService : IfaceService
    {
        public int wordLen(string word)
        {
            return word.Length;
        }
    }
}

<system.serviceModel>
   <services>
      <service behaviorConfiguration="wcfLib.Service1Behavior" name="wcfLib.Service1">
        <endpoint address="" binding="wsHttpBinding" contract="wcfLib.ser">
          <identity>
            <dns value="localhost" />
          </identity>
        </endpoint>
        <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange" />
        <host>
          <baseAddresses>
            <add baseAddress="http://localhost:8732/Design_Time_Addresses/wcfLib/Service1/" />
          </baseAddresses>
        </host>
      </service>
    </services>
    <behaviors>
      <serviceBehaviors>
        <behavior name="wcfLib.Service1Behavior">
          <serviceMetadata httpGetEnabled="True"/>
          <serviceDebug includeExceptionDetailInFaults="False" />
        </behavior>
      </serviceBehaviors>
    </behaviors>
  </system.serviceModel>