DevForce Community Forum : Need help with casting

Need help with casting : Yes, you can return whatever you...

Thu, 23 Dec 2010 08:22:32 -700

Author: kimj
Subject: 2393
Posted: 23-Dec-2010 at 8:22am

Yes, you can return whatever you want.

Need help with casting : Can I return an observablecollection...

Thu, 23 Dec 2010 08:19:53 -700

Author: BillG
Subject: 2393
Posted: 23-Dec-2010 at 8:19am

Can I return an observablecollection from a Coroutine?

Need help with casting : If you're returning an En...

Thu, 23 Dec 2010 08:17:13 -700

Author: kimj
Subject: 2393
Posted: 23-Dec-2010 at 8:17am

If you're returning an EntityQueryOperation from the Coroutine, then grab its Results -

var op = steps.Result as EntityQueryOperation;

var results = op.Results;

I'm wondering why the return from the Coroutine is an EntityQueryOperation; it might be a bit simpler to return just the desired results from it, not a *Operation.

Need help with casting : My code calls a Coroutine which...

Thu, 23 Dec 2010 07:45:55 -700

Author: BillG
Subject: 2393
Posted: 23-Dec-2010 at 7:45am

My code calls a Coroutine which performs a couple of queries and calculations and finally returns

Ideablade.EntityModel.CoRoutineOperation. Which in this case is assigned to step in the following piece of code.

var steps = Coroutine.Start(() => AvailableStepsSelector.RetrieveAvailableSteps(currentEvent));

steps.Completed += (sender, args) => {

if (args.CompletedSuccessfully) {

var type = steps.Result.GetType(); // type = Ideablade.EntityModel.EntityQueryOperation [EventStepType]

var results = steps.Result as IEnumerable<EventStepType>; // before the assignment 25 rows --- after null

ResetStepTypesList(results);

}

When I do a GetType() on steps.Result, I get an Ideablade.EntityModel.EntityQueryOperation [EventStepType], which is fine. On the very next line I cast steps.Result as IEnumerable and the assign it to results, thinking that results will now hold the returned data. WRONG, it is null. My ultimate goal is to pass results to ResetStepTypesList where I will do the following

public void ResetStepTypesList(IEnumerable

{

StepTypes.Clear(); //StepTypes is an ObservableCollection of EventStepType

StepTypes.ForEach(results.Add);

}

What am I doing wrong here between steps.Result and var results?