Enable MEX in a Web.Config

How do I enable/create a MEX endpoint in the below web config so I can view the service from my browser?

I have tried a few variation from googling but VS always complains about it. (not a valid child element etc...)

<configuration>
 <system.web>
  <compilation debug="true" targetFram开发者_C百科ework="4.0" />
  </system.web>
   <system.serviceModel>
    <serviceHostingEnvironment aspNetCompatibilityEnabled="true"/>
    <services>
     <service name="MyApp.MyService" behaviorConfiguration="WebServiceBehavior">
      <endpoint address="" binding="webHttpBinding" contract="MyApp.IMyService"       behaviorConfiguration="JsonBehavior">
        <identity>
          <dns value="localhost"/>
        </identity>
      </endpoint>
    </service>
   </services>
   <behaviors>
   <endpointBehaviors>
      <behavior name="JsonBehavior">
       <webHttp/>
     </behavior>
   </endpointBehaviors>
 </behaviors>
 </system.serviceModel>
 </configuration>

Cheers, Conor

In VS, go Tools > WCF Service Configuration Editor. You can open your web.config and tinker with your WCF endpoints and bindings in a nice GUI that (shouldn't) generate XML that VS will complain about.

Add this line to the web.config right under the service endpoint:

<endpoint address="mex" binding="mexHttpBinding" name="MetadataEndpoint"
 contract="IMetadataExchange" />

Thanks josh3736 for the tip on the GUI editor, the only problem I had was I still didn't know how to use the editor to do this, so here is what I did:

1. In VS, open Tools/WCF Service Configuration Editor
2. Open the web.config or app.config file that contains your service definition
3. Navigate to the Services / (your service) / Endpoints folder
4. If the MetadataEndpoint is there, click on it and edit the configuration to your liking, otherwise, right-click the Endpoint folder then click New Service Endpoint and configure like the one in the image below.

Just add System.ServiceModel.dll under references of your VS Project where your Web.config file is present.

Then add the below code in Web.config(like other service endpoints):

<endpoint address="mex" binding="mexHttpBinding"
contract="IMetadataExchange"/>