Question

I decided that returning datasets, working with datasets and datatables in a front end app is a rather bad idea. So with the magic of generics I am returning a generic list via Webservice call (not WCF just plain ol’ asmx). That works dandy as long as you need to return one list per call to your webservice.

The scenario I am running into is that I have a more involved screen where there are a few dropdowns and so on. I need to bind those dropdowns to a generic list. Problem is that I don’t want to make several web calls, one for each dropdown, to get my data. In the past I would have just returned a dataset and bound a dropdown to a specific table in the dataset.

So, it would be super to return multiple generic lists in one web call.

Things I’ve tried:

1. Using a List of Lists
2. Using a Collection of generic Lists
3. Creating a base class and using a Collection of List<Base>, there are conversion issues there when trying to stuff objects into that List<Base>.
4. Creating a class that has properties that return List<MyOneObject>, List<MySecondObject>, etc. That works but it’s kinda messy… I have lots of classes and screens in the app where this would happen. I could create a class like this that has a properties of List<MyType> for each class, but like I said I think that may get out of control.

So at this point I have two options, #4 in the above list, or just return a dataset which I would prefer not to do :0)

Has anyone run into this before?

Answer 1

Well I don’t think returning multiple lists is a good idea, but if you are going to do it, I would create a wrapper class with each list exposed as a property in that class.

Something like

class Wrapper
{
   public List<object1> Object1List {get;set;}
   public List<object1> Object2List {get;set;}

}