Channel 9 - Discussions by BenDi

Tech Off - How do I show a control outside the Form?

BenDi — Sat, 25 Mar 2006 15:12:55 GMT

Yup, that did the trick. Thanks!

Tech Off - How do I show a control outside the Form?

BenDi — Thu, 23 Mar 2006 15:39:36 GMT

Hi,

I'm trying to make a VS-like auto-complete control and can't figure out how to display it so it isn't clipped by the main Form. In VS, it looks like that: (as you can see, the auto-complete list is not clipped by the border of the VS main form)

I tried to put my selection list into a control which got me that far:

Does anyone have an idea how to get a control shown over the bounds of the form? Sadly, taking another form to put it in is not an option since the thing has to be visible while the focus is on the TextBox.

Cheers,

B.

Tech Off - To WPF or not to WPF?

BenDi — Sat, 11 Feb 2006 02:36:29 GMT

From my experiments with Sparkle (the Expression WPF Designer) it's not only fun and fast to build really cool apps but they seem to run stable (I never saw one of mine crash... didnt try running them for very long though). I'd say just give it a shot.

Tech Off - Generic Type Casting - Unsolveable?

BenDi — Sat, 19 Nov 2005 00:11:21 GMT

Thanks for the feedback so far. You're right that an interface would solve it if it was about modifying the Bs.

But the truth is that the core logic doesn't really care about anything B implements. It only wants to create the business objects (dynamically creating Bs, but working with them as As) and put them into the list.

The calling component however knows that it does not just get any list from the core but a list of Bs, so it thinks it should be possible to actually get a typed list of Bs back from the core.

I realize that this is more of a convenience issue, but isn't generic typing all about preventing coding errors through type safety? If I get a list of As back and only I know that they are all Bs, that doesn't measure up to that safety.

BTW: What really puzzles me about all that business is that Array implicitely has this functionality (B[] is not really derived from A[], but still the 'as' operator works) - while it seems to be impossible to replicate this behaviour in my own code.

Tech Off - Generic Type Casting - Unsolveable?

BenDi — Fri, 18 Nov 2005 04:05:12 GMT

What is wrong with the formatting? If I can make anything clearer I'd be happy to answer a question, but I'm pretty sure it makes sense this way.

Tech Off - Generic Type Casting - Unsolveable?

BenDi — Fri, 18 Nov 2005 02:59:58 GMT

Hello,

I have run on a problem and cant seem to find a way out of it.

Basically, I need to do for generic collections what

DerivedType[] DT = new DerivedType[10];
BaseType[] BT = DT as BaseType[];

does for arrays: to cast the generic type down in the hierarchy. It struck me as a bit odd that List is not convertible to List, so I started to investigate. Let me give an example:

public class A
{
...
}

public class BusinessLogic
{
   public static void FillList(SomeListClass L)
   {
   ...
   }
}

// and in another component:
public class B : A
{
...
}

public class CallingCode
{
   public static SomeListClass GetList()
   {
     // create a list of Bs
     // call BusinessLogic.FillList
     // return list
   }
}

The catch is that I want the core business logic to output lists that are conveniently typed in the (dynamicly determined) fitting type of the business objects. Since the core logic does not yet know about those types and they are dynamically assigned, it can only work on Lists of 'A'.

There is no way around this, I have to be able to create a list of As from a list of Bs. But of course it's not possible to just copy the list or even perform an array cast at the low level because the core logic adds a lot of objects (extending the list) and they should be dynamically seen in the original list of Bs. All I need to do is to 'reinterpret' the list of Bs as a list of As.

It would be no problem to design a list from ground up to support this, but I have spent some time thinking about it and cant see any solution, so Im happy about any thoughts you might have.

B.

Coffeehouse - What about Mono?

BenDi — Wed, 11 Aug 2004 18:53:09 GMT

Ok, now we have all the standard arguments out of the way - thanks so far.
The thing I'm wondering about is the potential that no one sees in Mono. Why does Mono compete with MS? I hope you dont think that all programs written in Mono are under the GPL... (and in what way does Novell gain from Mono, Jeremy?)
I mean why did MS make the .NET platform free in the first place? In my opinion, they did it because they hoped for the broad acceptance of the community, so that people would start using it because its a great platform.
Do you have any idea how many more people will program for .NET if it runs on Linux, Unix, Mac... I mean seriously, isn't this a huge opportunity for MS to start selling products to all those other users - without any more effort than to bring the managed world there (for instance by providing a bit System.Windows.Forms code)?
I'm open for all the different opinions you might (and will have.

Coffeehouse - What about Mono?

BenDi — Wed, 11 Aug 2004 17:59:45 GMT

This is a thing that is on my mind for a long time: What does the MS comunity think about Mono? I have talked with some guys in the Mono dev newsgroup and was surprised how little Microsoft seems to care about the thing.
Wasn't .NET supposed to be a plattform-indepent system? (Well it is, but the only supported plattform still is Windows...)
So the important questions are: Why shouldn't MS support Mono? How could MS support Mono?
Just tell me what you think...

Tech Off - Reference Parameters in C#

BenDi — Sat, 03 Jul 2004 11:35:58 GMT

If you only want to call methods on an existing object, there is no need to pass it as 'ref'.

void DoFoo(IFoo param)
{param.Modify();}

will work just fine. And there you will have downcasting.

Cheers

Ben