Is basicHttpBinding really required when exposing a WCF service as a Web Service for .NET 2.0 Target Client?

Question

I have a WCF service and am hosting it in a Windows Service.

I tried to add a reference for the service from a Windows Form client built on .NET 2.0. I could get the Web Reference by pointing to the httpGetUrl="http://localhost:8002/HBAccess/help/mex" but when I check the Reference.cs---It only contains a namespace with nothing in it.

Now I add the basicHttpBinding and repeat the same steps:

And now I can see the classes for the web service.

My senior colleague insist that setting the httpGetEnabled to true would be sufficient to export the WCF service via http and make a proper web reference.

Could anyone point me to what I am missing here?

<system.serviceModel>
<services>
  <service behaviorConfiguration="HBAcsNX.HBAccessBehavior" name="HBAcsNX.HBAccess">
        <!--<endpoint address="" binding="basicHttpBinding" contract="HBAcsNX.HBAccess" />-->
        <endpoint address="HBAccess" binding="netTcpBinding" contract="HBAcsNX.HBAccess" />
        <endpoint address="mex" binding="mexHttpBinding" contract="IMetadataExchange" />
        <host>
          <baseAddresses>
                <add baseAddress="net.tcp://localhost:18264/HBAccess/" />
                <add baseAddress="http://localhost:8002/HBAccess/" />
          </baseAddresses>
        </host>
  </service>
</services>
<behaviors>
  <serviceBehaviors>
        <behavior name="HBAcsNX.HBAccessBehavior">
          <serviceDebug includeExceptionDetailInFaults="True" httpHelpPageUrl="http://localhost:8002/HBAccess/help" />
          <serviceMetadata httpGetEnabled="true" httpGetUrl="http://localhost:8002/HBAccess/help/mex" />
        </behavior>
  </serviceBehaviors>
</behaviors>
</system.serviceModel>

// Resulting Reference.cs (Empty proxy stub with only namespace)

#pragma warning disable 1591
namespace Form.ServiceClient {
}
#pragma warning restore 1591

Answer 1

You have to specify a binding, and basicHttpBinding is the only one that interoperates with a .NET 2.0 client. .NET 2.0 ASMX clients only support XML over HTTP, and with no WS-* protocols.

Answer 2

Your config doesn't quite line up.....

<service name="HBAcsNX.HBAccess"
         behaviorConfiguration="HBAcsNX.HBAccessBehavior" >
   <host>
       <baseAddresses>
            <add baseAddress="http://localhost:8002/HBAccess/" />
       </baseAddresses>
   </host>

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

If you take all this into account, you get http://localhost:8002/HBAccess/ from the base address, plus mex from the MEX endpoint --> http://localhost:8002/HBAccess/mex

But in your behavior configuration, you use a different address for MEX:

<behavior name="HBAcsNX.HBAccessBehavior">
    <serviceMetadata httpGetEnabled="true"
                     httpGetUrl="http://localhost:8002/HBAccess/help/mex" />
</behavior>

Here, you point at http://localhost:8002/HBAccess/help/mex - note the extra /help in there. Now which one is it really??

I would recommend tossing away the explicit httpGetUrl in the service behavior config - just use:

<behavior name="HBAcsNX.HBAccessBehavior">
    <serviceMetadata httpGetEnabled="true" />
</behavior>

and you should be able to get your MEX at http://localhost:8002/HBAccess/mex.

Marc

Answer 3

the problem is mexHttpBinding isn't actually exposing your service, its only exposing a defenition of your service, and since .net 2.0 doesn't understand nettcp you get an empty namespace, you need basicHttpBinding becuase that is your actually service endpoint.

if you look at the contracts you see that the contract for mexHttpBinding isn't even "HBAcsNX.HBAccess" but rather "IMetadataExchange".