LabVIEW
Dynamic Calling of DLL
"Karen Breban" wrote in message
news:ap5vij$ct9$1@knossos.btinternet.com...
> Hi, is it possible in labview to call a dll dynamicaly. I have a VI which
> can call one of multiple dlls, at compile time i do not know what the name
> of the dll will be, this is passed to the VI as a variable. I can see no
> way of calling a dll (even if i know they all have the same prototye) by
> variable name, can anyone help ????
>
>
As the others stated, this cannot be done.
Another workaround might be to do the following.
Let a loader VI (a VI that loads the rest of the program) deside what dll
should be used. Copy this dll to the application directory, and give it a
general name (e.g. WorkingVersionOfDll.dll). Use this dll in the main
program. Af
ter the loader changed the WorkingVersionOfDll.dll, dynamically
load and start the rest of the program.
The loader is neccessary because LV loads the dll into memory when the VI's
are loaded. So changing the dll after this will result in a lot of trouble.
It's not very nice, but it will probably work.
Regards,
Wiebe.
news:ap5vij$ct9$1@knossos.btinternet.com...
> Hi, is it possible in labview to call a dll dynamicaly. I have a VI which
> can call one of multiple dlls, at compile time i do not know what the name
> of the dll will be, this is passed to the VI as a variable. I can see no
> way of calling a dll (even if i know they all have the same prototye) by
> variable name, can anyone help ????
>
>
As the others stated, this cannot be done.
Another workaround might be to do the following.
Let a loader VI (a VI that loads the rest of the program) deside what dll
should be used. Copy this dll to the application directory, and give it a
general name (e.g. WorkingVersionOfDll.dll). Use this dll in the main
program. Af
ter the loader changed the WorkingVersionOfDll.dll, dynamically
load and start the rest of the program.
The loader is neccessary because LV loads the dll into memory when the VI's
are loaded. So changing the dll after this will result in a lot of trouble.
It's not very nice, but it will probably work.
Regards,
Wiebe.
Search LabVIEW like a graph!
Hi,
I've build set of vi's (and a small dll) to do this. Error handling is very
important. If a pointer cannot be found, you don't want to call it (jump to
NULL)!
I'll zip it and mail it to the group. Please reply to this thread, I can't
see mails with attachments, or replies to it.
There's an example. It's kinda fun to use. By changing the input for the
load function between a labview dll, and user32 dll, you use a standard
messagebox, or a custom messagebox.
There are two ways to use it. First it to store the address. By calling
CallStoredAddress with the normal input configuration of the dll, the
function is called. The second way is to call CallDll. This function assumes
that the first input is the address of the function.
Re
gards,
Wiebe.
"Karen Breban" wrote in message
news:ap9118$6be$1@venus.btinternet.com...
> Cheers for the help, any chance you could send me an example of how to do
> this. Thanks Tom.
>
>
I've build set of vi's (and a small dll) to do this. Error handling is very
important. If a pointer cannot be found, you don't want to call it (jump to
NULL)!
I'll zip it and mail it to the group. Please reply to this thread, I can't
see mails with attachments, or replies to it.
There's an example. It's kinda fun to use. By changing the input for the
load function between a labview dll, and user32 dll, you use a standard
messagebox, or a custom messagebox.
There are two ways to use it. First it to store the address. By calling
CallStoredAddress with the normal input configuration of the dll, the
function is called. The second way is to call CallDll. This function assumes
that the first input is the address of the function.
Re
gards,
Wiebe.
"Karen Breban"
news:ap9118$6be$1@venus.btinternet.com...
> Cheers for the help, any chance you could send me an example of how to do
> this. Thanks Tom.
>
>
