当发布wcf service 出现类似如下错误时，表示你的配置文件有问题：
This is a Windows© Communication Foundation service.
Metadata publishing for this service is currently disabled.
If you have access to the service, you can enable metadata publishing by completing the following steps to modify your web or application configuration file…
上面的错误指出：缺少Metadata 节点，因此我们可以在我们的wcf配置文件中添加Metadata 节点，并设置httpGetEnabled 属性为ture.
