Data not coming through from RIA Services in Silverlight - wcf

I had a connection working but something changed and now the data isn't showing up. It is a simple query that worked before that just returns all entities. I put in break points on the LoadOperation call and it fires and gets 0 entities. I also put a break point on the service itself, and it does not break before the LoadOperation evaluates. After the LoadOperation completes, then the service query is called... well after we needed the data. The only thing that I can think of that could be a problem is that I added 2 WCF services to the solution. Would WCF services stop the RIA from working? Any ideas on what else could cause the problem?
Client:
LoadOperation<Project> loadOp =
this._projectContext.Load(this._projectContext.GetProjectsQuery());
Service:
public IQueryable<Project> GetProjects()
{
return this.Context.Projects;
}
See, real basic, but not working.

You need to put a callback method on your Load operation and then check the results of the LoadOperation.Error when it comes back. In that error you will find the exception which will let you know what the problem is (you will probably have to check the inner exception to get the full details).

Related

WCF - Return and continue processing

I have a WCF method.
I would like to return to user a result and continue processing in the server side (via .net Task).
The problem is that I have the "Cannot access a disposed object." error message when I continue processing in the server side.
can anyone help ? how can I implement that. Return a result to user but continue working in the server side.
thanks
Hagai
explore callback contract option for your scenario - http://www.dotnetcurry.com/ShowArticle.aspx?ID=721

Internal fault in MS auto-generated method of WCF

I have a problem with WCF. My testing code is pretty simple.
I call a service layer method on my server from my silverlight application and print the result in a textbox.
Everything of this is surrounded by try-catch.
When my service layer method simply returns a constantly defined string there seems to be no problems - however as soon as it calls a more complex method it fails.
While debugging it does not even reach the complex model method; it fails before that inside some auto-generated code from microsoft:
/WuSIQ.jpg
As the error message "NotFound" is not exactly the most helpful or specific you can imagine my trouble googling for hints.
I thought maybe the auto-generated code could only send simple data so I made a temporary string and returned that, but this did not help.
I have already: a client access policy, a service reference added, removed duplicate reference in ServiceReferences.ClientConfig and a ServiceLayer.svc.cs.
I am debugging by running from the main window and my breakpoints are picked up.
Anyone?
I had some errors in the server side method that were quickly found after debugging was fixed.
I fixed this, as I said in comments, setting the project to have "Multiple Startup Projects".
Whenever I had troubles with updating the WCF service methods one of these usually solved it all:
1 Delete all bin and obj folders (specifically selecting re-build might do the same).
2 The servicelayer will not succesfully auto-update (but will work!) unless this:
[ServiceContract(Namespace = "")]
... is set to this:
[ServiceContract(Namespace = "YourServiceLayerName")]
3 Right clicking on the servicereference and selecting "update...".
Sometimes it would stop debugging again, but a forced full re-build would return it to normal.
I hope this helps someone.

WP7 and WCF Services: Fast app switching

I'm currently building a WP7 app that consumes WCF Data Services hosted on a web server. What I'd like to deal with is
cathayService.ServiceException += (sender, e) =>
{
Debug.WriteLine(e.Exception.ToString());
MessageBox.Show(e.Exception.ToString(), "Service Error", MessageBoxButton.OK);
};
The service exception triggers if I have a lack of internet connectivity. It also triggers when I face with fast app switching. How'd I be able to differentiate the source of the ServiceException?
Hope someone can give me an idea... Many thanks! :)
[It's unclear if you are getting a ServiceException instance, or if you are referring to the ServiceException event in some places above]
Check the exception you get - if it's typed as ThreadAbortException, that means you are being switched out. If you actually get a ServiceException thrown, check it's inner Exception and see if THAT guy is ThreadAbortException.
My suggestion is that you don't hook that event though and instead use the actual callback events on the WCF client to check the .Error property of the EventArgs you get back.

Throwing exception in WCF service operation, anything to look out?

I am just learning WCF and wrote a Windows Service hosting a WCF service. Ever since I started it in service.msc in the remote server (physically remote, and very slow) I think I have already hit and fixed like a hundred errors here and there already. I am now finally stuck.
At this point, I have enabled tracing and message logging. The first and only function call looks like this:
[OperationContract]
public MyServiceResponse ConnectToAXDynamicsViaDotNET2BusinessConnectorWithSadFace()
{
try
{
throw new NotImplemented();
}
catch(Exception ex)
{
return new MyServiceResponse(ex, ex.Message);
}
}
[DataContract]
public class MyServiceResponse
{
// ...
}
Upon calling the operation, the client just sits and waits until timeout. Checking the trace, it records my thrown exception. So it makes me wonder if WCF actually blocks there and ignore my catch clause.
I then tested with just a simple return value without throwing and it FINALLY works.
My question is, how then can I make the above scenario work, ie. catch the exception and return a sensible result back to client? Maybe it's just the tracing that blocks me, but I want to enable tracing during this whole debugging process otherwise it's really hard to work.
Thanks for your precious help!
EDIT: Sorry, I found this right after I posted this question. Happens all the time: http://msdn.microsoft.com/en-us/library/ee942778.aspx but I have yet to read it as I got to run off now. Not sure it it will solve my problem.
Risk being downvoted, but just for documentation sake and general usefulness of having this question:
Through reading the FaultException handling articles, I guess the above behavior is due to Exception class not serializable. And the service silently disconnects itself without returning any error messages eventhough the "send (unknown) faults to client" is enabled. As for why it does so, I have no idea yet. Will update if I find out more.
I have since changed to throw new FaultException() instead of returning my own MyServiceResponses.

WCF Catastrophic Failure

I've got a real lemon on my hands. I hope someone who has the same problem or know how to fix it could point me in the right direction.
The Setup
I'm trying to create a WCF data service that uses an ADO Entity Framework model to retrieve data from the DB. I've added the WCF service reference and all seems fine. I have two sets of data service calls. The first one retrieves a list of all "users" and returns (this list does not include any dependent data (eg. address, contact, etc.). The second call is when a "user" is selected, the application request to include a few more dependent information such as address, contact details, messages, etc. given a user id. This also seems to work fine.
The Lemon
After some user selection change, ie. calling for more dependent data from the data service, the application stops to respond.
Crash error:
The request channel timed out while waiting for a reply after 00:00:59.9989999. Increase the timeout value passed to the call to Request or increase the SendTimeout value on the Binding. The time allotted to this operation may have been a portion of a longer timeout.
I restart the debugging process but the application will not make any data service calls until after about a minute or so, VS 08 displays a message box with error:
Unable to process request from service. 'http://localhost:61768/ConsoleService.svc'. Catastrophic failure.
I've Googled the hell out of this error and related issues but found nothing of use.
Possible Solutions
I've found some leads as to the source of the problem. In the client's app.config:
maxReceivedMessageSize > Set to a higher value, eg. 5242880.
receiveTimeout > Set to a higher value, eg. 00:30:00
I've tried these but all in vain. I suspect there is an underlying problem that cannot be fixed by simply changing some numbers. Any leads would be much appreciated.
I've solved it =P.
Cause
The WCF service works fine. It was the data service calls that was the culprit. Every time I made the call, I instantiated a new reference to the data service, but never closed/disposed the service reference. So after a couple of calls, the data service reaches its maximum connection and halts.
Solution
Make sure to close/dispose of any data service reference properly. Best practice would be to enclose in a using statement.
using(var dataService = new ServiceNS.ServiceClient() )
{
// Use service here
}
// The service will be disposed and connection freed.
Glad to see you fixed your problem.
However, you need to be carefull about using the using statement. Have a look at this article:
http://msdn.microsoft.com/en-us/library/aa355056.aspx