This should be simple | Tech Off

adrian.h
Would rather be camping or climbing!

Hi, this should be a stupidly simple question, but for some reason, I can't find reference to it anywhere. Must be the keywords I'm using, cuz this is a big reason for the CLR.

I want to write an assembly like a COM or ActiveX control. It needs to have usable controls, encapsulate the internals and expose a usage and event interface. It should be able to be dropped into a VB and a LabVIEW application.

This is so simple, I don't know why I can't find any reference to it.

Any help would be greatly appreciated.

Adrian

spivonious

If I'm understanding you correctly, search for "COM Interop"

adrian.h
Would rather be camping or climbing!

In reply to spivonious

#Sep 2nd, 2008 @ 12:40 PM

So it sounds like you are saying that I cannot create a .NET assembly without the use of a COM interface. That doesn't sound right.

My co-worker is using LabVIEW and is interfacing with the pre-loaded .NET assemblies that were DLed when installing the .NET libraries.

Anyone else that has a suggestion as to where I can find the info I am looking for?

Thanks

spivonious

In reply to adrian.h

#Sep 2nd, 2008 @ 12:52 PM

As far as I know, there's no way to use a .NET assembly outside of .NET without making a COM interface for it, but I may be wrong.

Yggdrasil
Pour me a cab, 'cause I can't drink no more.

Didn't we have this here a few days ago?
You can't create ActiveX controls with .NET, unfortunately. What you CAN do is create a .NET component, with all the controls and events and so forth that you want. If LabVIEW is a .NET host, you can plunk those controls into it just like you would a COM component in a COM host. Looking here, it seems that LabVIEW can host .NET controls. This page mentions "all .NET components registered globally", so I'm guessing it looks in the GAC.
What you need to do is this:
1) Create a Windows Forms Class Library project in Visual Studio.
2) Design the user controls you want using C#/VB.Net, whatever.
3) Sign your assembly with a strong-name key (Right click on the project -> Properties -> Signing).
4) Register your component in the GAC by copying the DLL over into C:\Windows\assembly.
5) Follow the instructions in the link above to add it to your LabVIEW project.

adrian.h
Would rather be camping or climbing!

In reply to spivonious

#Sep 2nd, 2008 @ 12:55 PM

Hmmm, well, after talking to my colleague, they must be different since they use a separate container in LabVIEW.

I know that you can wrap an assembly in an AX/COM component. But I would like to bypass this as it should be unnecessary.

adrian.h
Would rather be camping or climbing!

In reply to adrian.h

#Sep 2nd, 2008 @ 1:10 PM

Ok, but I'm confused. If I have a class that is this:

namespace WindowsFormsApplication3
{
    static class Program
    {
        /// 
        /// The main entry point for the application.
        /// 
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Form1());
        }
    }
}

(which is the default class generated when creating a form app) do I just add members functions to this and they will be callable? How do I do event callbacks?

adrian.h
Would rather be camping or climbing!

In reply to adrian.h

#Sep 2nd, 2008 @ 1:18 PM

My last message was in response to Yggdrasil.

Yggdrasil
Pour me a cab, 'cause I can't drink no more.

In reply to adrian.h

#Sep 2nd, 2008 @ 1:18 PM

Don't create a Windows Forms app. Create a Windows Forms Control Library.
Also, I think "How to write a windows forms control" is a bit of a large topic to cover here. I found a quick tutorial here which doesn't cover much, but googling for "windows forms" and "tutorial" will probably net you a couple of more examples.,

adrian.h
Would rather be camping or climbing!

In reply to adrian.h

#Sep 2nd, 2008 @ 1:19 PM

Ahh. I see it. thanks

Yggdrasil
Pour me a cab, 'cause I can't drink no more.

In reply to adrian.h

#Sep 2nd, 2008 @ 1:23 PM

Hmm. What version of Visual Studio are you using? I'm on VS 2008 Professional, but it might not be included in VS Express.
If so, just create a standard Class Library and add a reference to System.Windows.Forms manually, and see if it lets you add a new User Control item to the project.

adrian.h
Would rather be camping or climbing!

In reply to Yggdrasil

#Sep 2nd, 2008 @ 1:25 PM

VS 2008 Professional Ed.

Can I put a AX control into this form? Under VS C++ 6 you right clicked and added an AX control. VS2008 doesn't seem to have that functionality, at least in a way that is easy to find.

Yggdrasil
Pour me a cab, 'cause I can't drink no more.

In reply to adrian.h

#Sep 2nd, 2008 @ 1:33 PM

In the toolbox, right click and Choose Items. There you have tabs on top to select COM components.

adrian.h
Would rather be camping or climbing!

In reply to Yggdrasil

#Sep 2nd, 2008 @ 1:39 PM

Excellent! Now I just need to figure out the interface (your example was in VB, I need C#) and I'm good to go. Smiley

Sanks!

adrian.h
Would rather be camping or climbing!

In reply to Yggdrasil

#Sep 2nd, 2008 @ 1:39 PM

Actually, your example doesn't show anything about interfacing to the outside world. Sad

Oh well.

PerfectPhase
"This is not war, this is pest control!" - Dalek to Cyberman

In reply to adrian.h

#Sep 2nd, 2008 @ 2:01 PM

To call a .Net component from COM you need to understand the COM Callable Wrapper (CCW) http://msdn.microsoft.com/en-us/library/f07c8z1c.aspx

To call a COM object from .Net you have to go through the Runtime Callable Wrapper (RCW) http://msdn.microsoft.com/en-us/library/8bwh56xe.aspx

To call an unmanaged dll from .Net you have to use Platform Invoke (PInvoke) http://msdn.microsoft.com/en-us/library/aa288468.aspx

What do you actually want to do?