Problem with a DLL Pointer and Pointer to Pointer in LabVIEW

[wiebe@CARYA]

---

@rolfk wrote:

As to callback functions in a DLL from LabVIEW VIs, that is a concept that I pondered a few times but considered it simply not practical. I consider the solution more brittle than a spider rag, a total maintenance nightmare and pretty much nothing I would ever want to support for average LabVIEW users. They don't understand the difficulties and will mess up over and over again. If you can't write C code to implement the callback functions yourself (one of the more advanced C programming topics) you can't really comprehend the difficulties not even for just using an existing solution. But if you know how to write the according C code, its simply a ten fold simpler to do it that way than trying to do callback functions in LabVIEW.

---

I can write a callback function in LabVIEW, by compiling to a dll, that's no problem.

I prefer a LV dll (over C), because the LV dll function can easily call a VI by reference, and this VI can easily communicate with the 'user space' (dev.env or exe). DVR references stopped working this way in LV24 though...

The only problem is the callback VI needs two inputs for each pointer input\output. You can't use a 64 bit integer as a pointer input\output for a 32 bit dll... And vice versa.