LabVIEW
Compiled .exe only works if I allow it to prompt me for .dll files
Solved!
Windows DLL search path issue!
LabVIEW only can know about the DLLs that it directly calls. It places them in the data directory by default and adjusts the calling paths in the code to account for that.
Your uEye driver however consists of many secondary dependencies that you copied yourself into that folder too. Now what happens is this:
LabVEW requests from Windows to load A.DLL from .\data\a.dll. Windows tries to load the DLL and sees, aahh it needs also B.DLL. But it has no information where this B.DLL exists. So it starts a search at these locations:
1) already loaded in memory? use that!
2) inside the directory where the current processes exe file is located? load that!
3) inside C:\Windows\System32? load that!
4) inside C:\Windows? load that!
5) inside the current working directory? load that!
6) inside any directory listed in the PATH environment variable? load that!
7) sorry pal I can't load this DLL!
LabVIEW then prompts you to locate the DLL and you go into the data folder and select it.
But the Windows file dialog that LabVIEW uses has one insidous side effect when you browse to a file and select it with the OK button: it also updates the current directory to the directory this file is located in.
Now the whole chain of searches starts again, only now in step 5 above, Windows suddenly can find B.DLL that is located along A.DLL and bang, huge success!
The most simple solution is to update the Build specification for your executable to use for the Support directory the same location as your exe file. All DLLs are then copied into the application directory and Windows is totally happy as it can find your DLLs there according to step 2 in above search order.
The really correct solution would be if your driver was using a proper installer and put all its DLLs and other necessary support files in a commonly findable location itself.
Your runtime error would indicate that the DLLs somehow try to load some files (configurations files, plugin DLLs??) themselves using relative paths. The C runtime resolves such paths relative to the current directory, which unless you mess around with changing this, or selecting a file dialog, should be initialized at process startup to the same directory as where your executable is located. Most likely there are some other files than just DLLs that you need to place in the same folder too. But ultimately the uEye driver is badly flawed in that it makes to many assumptions.
The way you describe it it was your wanting to be smart that caused the problems. 😀
The existence of the uEye_api.dll in system32 would indicate that the uEye driver actually comes with a proper installer that places everything where it should be.
Of course the LabVIEW specific wrapper DLL is most likely not part of the official uEye driver installation and may even have been developed by an independant third party. In that case it should not hurt to leave this DLL in the default data directory that LabVIEW creates for a build. Most likely by not copying all the uEye driver DLLs into your LabVIEW build it should still work. Or maybe not, I have never looked at that driver so can't know for sure how it is built up. From what I have seen in some posts it seems to be a collection of several DLLs that each support different camera types and also support DLLs from third party libraries that the driver uses, including various GPL and other other open source libraries.
