How to dynamically load and unload .NET DLLs?

[Ben_V]

Hello,

I am trying to find a way to dynamically load and possibly unload .NET DLLs in LabVIEW. This is easy to do when you can use the "Call Library Function Node" to call your DLL by specifying its path on the block diagram. However, it doesn't seem like there is an easy way to do that for .NET DLLs.

I use the .NET constructor node to create an instance of my .NET object which is my DLL, and I use property or invoke nodes to access my DLL methods. 

Does anyone know how this can be done? 

Thank you for your help!

 

[Rolf Kalbermatter]

42 minutes ago, Ben_V said:

Hello,

I am trying to find a way to dynamically load and possibly unload .NET DLLs in LabVIEW. This is easy to do when you can use the "Call Library Function Node" to call your DLL by specifying its path on the block diagram. However, it doesn't seem like there is an easy way to do that for .NET DLLs.

I use the .NET constructor node to create an instance of my .NET object which is my DLL, and I use property or invoke nodes to access my DLL methods. 

Does anyone know how this can be done? 

Thank you for your help!

Not directly. But I solved that in the past by creating VIs that called the .Net (or ActiveX) nodes and then calling those VIs dynamically through VI Server. A sort plugin system with the dynamic called VIs containing the .Net or ActiveX nodes.

[Ben_V]

@Rolf Kalbermatter thank you for your answer. 

Is it possible to specify the path to the .NET DLL? The issue is that the .NET DLL location may change after I deploy it. 

Thank you!

[Rolf Kalbermatter]

15 hours ago, Ben_V said:

@Rolf Kalbermatter thank you for your answer. 

Is it possible to specify the path to the .NET DLL? The issue is that the .NET DLL location may change after I deploy it.

No it's not. A .Net DLL is not supposed to change location in build applications.

.Net itself only knows really two locations by default where it will search for assemblies:

- The directory in which the current executable file is located

- The GAC

Anything else is extra, such as an non-default AppDomain with its custom ApplicationBase.

LabVIEW adds to this the option to reference Assemblies by full path (which the application builder adjusts to the location you configured the assembly to be installed to) but that path is embedded in the compiled VI and not accessible just as you can't change the path of subVIs in a compiled executable either.