Silverlight client never calls WCF Service

Question

Hi all,

This one has me completed stumped. I have developed a silverlight application that calls back to WCF services ( it's a silverlight - basicHttpBinding)

The site works perfectly fine from my development machine, but when it is deployed to the developement server. The application is delivered with the XAP just fine, but it never attempts to talk to the service. I have a service call in the bootstrapper so it should be calling this when the client starts up. The services are healthy. They can be browsed to and show the standard WCF service display. We have been through the bindings many times and everything seems to be ok. I have added an extensive amount of error handling for displaying any errors, but on this dev server, no service calls and no errors are being raised.

Fiddler shows the page being loaded up, but my client never issues a call to the service. The service is in the same folder as the default.aspx which hosts the Silverlight client.

This is a Silverlight 3.0 app.

Anybody ever seen anything similar?

Answer 1

• Put a graphical display like "I made the call!" before the service invocation. just to be sure that your app is really trying to call the service... So we could narrow the search to a communication problem. : )

• Verify that there aren't any cross-domain rules stopping the app to make the call. by the way, are you calling a WCF service from another domain?

Answer 2

I will try to debug in three steps

1. Verify whether the hosted service on dev server is up or not, by hitting the service URL from your browser on your dev machine.

2. Make sure that ServiceReferences.ClientConfig consists ur hosted service URL and not dev machine service URL.

3. If still error occurs try to debug your application from visual studio by pointing the endpoint address to http://urserver/urservicename.svc

Also make sure you dont have have cross domain problems by using "silverlight spy" tool

Answer 3

Are you sure the silverlight app is loading at all? If you are making the service call in the boot strapper and the call breaks, I assume that will lead to just a blank page. If you are seeing just a blank page, then perhaps there is something wrong with the .xap mime type issued from the server. Here is some more info on that:

http://learn.iis.net/page.aspx/262/configuring-iis-for-silverlight-applications/