topic Re: how to call a Component Object Model (COM) object in LabVIEW

how to call a Component Object Model (COM) object

slingee — Tue, 27 Jun 2006 13:24:31 GMT

Hello,

I am trying to call on a Component Object Model (COM) object from the shell32.dll but I don't know how.

I have tired the open library function vi but don't seem to be able to get through that way.

Thanks you your help in advance.

Re: how to call a Component Object Model (COM) object

Lycangeek — Tue, 27 Jun 2006 14:54:39 GMT

Use the nodes in the ActiveX palette. ActiveX is a specific type of COM, but the palette nodes work with any COM object. You can also take a look in examples/comm for examples using these nodes. Basically, you'll start with the Open Automation node to create the instance of the COM object (equivalent to the Win32 method CoCreateInstance) and then use the invoke and property nodes to access the instance.

Re: how to call a Component Object Model (COM) object

slingee — Tue, 27 Jun 2006 16:29:07 GMT

Hello Brian Tyler

I followed your instruction but I ran into another problem ~

I can't find the COM with the control

on this website

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/shellcc/platform/shell/programmersguide/shell_int/shell_int_programming/taskbar.asp

I have found this section that I want to use:

Modifying the Contents of the Taskbar

Version 4.71 and later of Shell32.dll adds the capability to modify the contents of the taskbar. From an application, you can now add, remove, and activate taskbar buttons. Activating the item does not activate the window; it shows the item as pressed on the taskbar.

The taskbar modification capabilities are implemented in a Component Object Model (COM) object (CLSID_TaskbarList ) that exposes the ITaskbarList interface (IID_ITaskbarList ). You must call the HrInit method to initialize the object. You can then use the methods of the ITaskbarList interface to modify the contents of the taskbar.

but I can't seen to find it.

Oh and I visited your blog, it is awesome, the nano car article is cool

thanks for your help

Jimmy

Re: how to call a Component Object Model (COM) object

Lycangeek — Tue, 27 Jun 2006 18:32:22 GMT

Glad you liked the blog 🙂 Yeah, that nano-car is almost unbelievable.

Okay, I've never used this control, so I'm not sure what type library it's defined in. I tried browing shell32.dll and comctl32.dll, but neither had it. I did some googling on CLSID_TaskbarList, but everything I found seems to indicate that there isn't a type library already built for it. Unfortunately, if it doesn't have a type library, you can't use it in LabVIEW. However, since so many people use it, you might be able to find an example program with an IDL defined for it. That can create a typelib.

Re: how to call a Component Object Model (COM) object

rolfk — Wed, 28 Jun 2006 05:47:22 GMT

@Lycangeek wrote:
Glad you liked the blog 🙂 Yeah, that nano-car is almost unbelievable.

Okay, I've never used this control, so I'm not sure what type library it's defined in. I tried browing shell32.dll and comctl32.dll, but neither had it. I did some googling on CLSID_TaskbarList, but everything I found seems to indicate that there isn't a type library already built for it. Unfortunately, if it doesn't have a type library, you can't use it in LabVIEW. However, since so many people use it, you might be able to find an example program with an IDL defined for it. That can create a typelib.

Lots of shell32 objects are rather rudimentar COM objects, using COM infrastructure but not implementing enough to be a real ActiveX object. Most also simply lack any typelib definition anywhere so won't be usable from any browsable ActiveX implementation like LabVIEW or Visual Basic anyhow.

Rolf Kalbermatter

Re: how to call a Component Object Model (COM) object

slingee — Wed, 28 Jun 2006 12:47:05 GMT

Hello

so following that thought, I would have to start some c code, but I don't have a c compiler, would labview be able to compile c code? My guess is no. So there is no way I can make this thing work then

Re: how to call a Component Object Model (COM) object

Lycangeek — Wed, 28 Jun 2006 14:33:26 GMT

Yeah, I'm afraid you must get a C/C++ compiler in this case - VB, LabVIEW, C#, VB.NET - all these languages require a type library before you can use the COM component. However, you might search around to see if anyone else has already created a type library for this. When I did a brief search yesterday, I saw several discussions amoung VB programmers - which gives good chances that there is one out there.

The other option is for you to create one yourself. That simply requires that you create an IDL file that defines the COM class (I saw segments of this in the search) and then compile the IDL file. I believe the IDL compiler is part of the Windows SDK, which is a free download.

Re: how to call a Component Object Model (COM) object

rolfk — Wed, 28 Jun 2006 14:42:09 GMT

@slingee wrote:

Hello

so following that thought, I would have to start some c code, but I don't have a c compiler, would labview be able to compile c code? My guess is no. So there is no way I can make this thing work then

LabVIEW is not a C compiler. So you will need another software (Visual C, Borland C, possibly MingW based compiler) if you want to do this.

Another possibility is to look for a LabVIEW Toolkit that does all this for you. There are two possibilities I know of:

- George Zou's library at http://www.geocities.com/gzou999/

- Inventeerings InvTray Toolkit at http://www.inventeering.com/Product_INVtray.html

Rolf Kalbermatter

Message Edited by rolfk on 06-28-2006 04:47 PM

Re: how to call a Component Object Model (COM) object

slingee — Wed, 19 Jul 2006 12:54:57 GMT

hello

It's been a while, but, here I am again.

I don't know what to do after I've got the IDL file. I can't install the window sdk into my company computer. Is there another way to get this working Brian?

Re: how to call a Component Object Model (COM) object

Lycangeek — Wed, 19 Jul 2006 15:52:10 GMT

I compiled the IDL for you, but I had to remove the IUnknownVB since that would not compile - and I'm not sure why you'd need it.

I'm afraid after this, you're off the trail and into the underbrush...good luck!

Re: how to call a Component Object Model (COM) object

slingee — Wed, 19 Jul 2006 16:13:41 GMT

Thanks a bunch,

I would give that a shot, but if I am going into the underbush, Thanks for the bush Knife

Re: how to call a Component Object Model (COM) object

slingee — Wed, 19 Jul 2006 19:10:26 GMT

Hello again:

Brian I thought I don't have to bug you again but I was wrong

I can't register the type library

http://digital.ni.com/public.nsf/allkb/4F811A9B23F1D46E862566F700615B7A?OpenDocument

didn't work. I tried to google up some methods and that doesn't work either. and then I tried hitting straight with Call Library Function and the whole labview shuts on me.

Re: how to call a Component Object Model (COM) object

Lycangeek — Wed, 19 Jul 2006 19:34:27 GMT

Well, you don't need to register the typelib - you can simply browse to it from the ActiveX selection dialog. The COM component itself (the shell) is already registered. I dropped an invoke node and selected the interface and was able to see the methods.

DON'T use Call Library node - use the ActiveX palette only for these things. If you need to call one of the Shell Win32 methods, however, you do use the Call Library Node.

Re: how to call a Component Object Model (COM) object

slingee — Mon, 14 Aug 2006 15:31:46 GMT

Hello Brian,

It's been a while but I have been away, so I might be much to ask. But here it is:

I am just wondering if you could tell me which reference I should use for the invoke node that I call these by?

thanks

Jimmy

Re: how to call a Component Object Model (COM) object

Lycangeek — Mon, 14 Aug 2006 16:50:12 GMT

I'm not sure what you are asking. You need to call the Automation Open node on the shell CoClass that you want, and then you can pass that refnum into the invoke node. ??? What exactly are you looking for?

Re: how to call a Component Object Model (COM) object

slingee — Mon, 14 Aug 2006 17:28:52 GMT

Oh I am actually trying to get this to work.

You see if this works Brian I can get rid of the extra tab or any tab that I don't need.

I don't really understand that shell co class part