使用自定义ClientCredentials的WCF身份验证:要使用的clientCredentialType是什么？

  <bindings>
    <wsHttpBinding>
     <binding name="myBinding">
       <security mode="Message">
         <message clientCredentialType="Custom" />
        </security>
      </binding>
    </wsHttpBinding>
  </bindings>
 <services>
   <service name="MyService">
     <endpoint address="http://localhost/MyService"
                binding="wsHttpBinding"
                bindingConfiguration="myBinding"
                contract="IMyService" />
    </service>
  </services>
</system.serviceModel>