@Tiago-M-Pinto said in Link Qt program with DLLs:
Could it be a compiler version issue?
@sierdzio already told you that only msvc2017 and 2019 are binary compatible. So recompile your lib with 2107 or 2019 and see if it still crashes - if it is the case take a look at the backtrace to see what goes wrong.
@filipdns said in SQLite database locked on localstorage example:
Following documentation, js transactions are suppose to automatically close db.
I think it will made more sense to do the DB work on C++ side and implement a QML/C++ interface to access to the data.
JS/QML is powerful to create/handle user interface, but to work with data C++ is the better choice!
The INCLUDEPATH seems to be correct. At least what you are showing.
I do not know the test library feature of boost. However, I know that some features require separate compilation which will create libraries. This would be for the regular expression of boost for instance. Those libraries need to be referenced with LIBS statement.
@aha_1980 said in QT and Matlab:
@jsulm said in QT and Matlab:
@alberto-brunero To add to @SGaist : on Windows LIBS syntax is different:
LIBS += "C:/Program Files/MATLAB/R2019b/extern/lib/win64/mingw64/libeng.lib"
That is not true. The correct way is to use -L... -l... on Windows too, as Creator then sets up the library search path for you.
Also, you should use / instead of \ in pro files, even on Windows.
I fully agree to that. Also, by all means avoid spaces in paths.
Agree with @aha_1980 about -L..., -l..., and / on Windows.
Spaces in LIBS are quite safe though; just wrap the path in double quotes:
LIBS += \
@Ace04 said in Unresolved external symbol _strerror_r error while executing libcurl with QT:
LIBS += -L"$$PRO_FILE_PWD/dependencies/SSL/lib/" libcrypto.a libssl.a
Your LIBS lines are wrong.
Correct would be: LIBS += -L"$$_PRO_FILE_PWD_/dependencies/SSL/lib" -lcrypto -lssl (Add -l, omit lib... and .a.
Also, convert all backslashes to forward slashes.
Also, remove all trailing slashes from the paths (INCLUDEPATH and LIBS)
There should also be a folder with the tests that ran. That's the one I am suggesting to check.
Note that there seems to be some mixing of forward and backward slash which might explain the failure. Use all forward slashes when giving parameters.
Unfortunately WinCC OA 3.15 requires no later than QT 5.5.1, MSVC 2013 and Win 64bit
I have downloaded a different file from https://download.qt.io/archive/qt/5.5/5.5.1/ and that does indeed seem to have resolved the compilation issue :)
I am now getting an error at runtime but could be something daft so I will look into more.
Fix this by copy / pasting a sample project into QuickQanava root after forking QuickQanava on GitHub. Rename the .pro, .pro.user and the folder. In the .pro file, put in the new path to the apparent .pri file.
It builds and runs now.
@Christian-Ehrlicher Thanks for your reply. I have used a newly installed machine with only qt 5.14 compiled, and I did not change any source code so it is strange if I by error have somehow included any Qt4 headers.
I see that the build also fails at https://github.com/KDAB/GammaRay (ERROR: could not open HSTS store at 'C:\Users\appveyor/.wget-hsts') but I guess this is unrelated.
I understand your frustration but there's nothing we can do here. Qt just provides tools. Someone just made a poor use of them. I'm a game engine programmer myself so I can tell you that it can be hard to diagnose these types of issues and it is often hard to even know they exist. It might be a bug, bad network design or a simple case of "works on my machine". Sometimes it's an entirely different team that makes a crappy launcher for otherwise good game or vice versa.
Try to contact the creators. Developers often don't read forums but there's a lot of them on social media like twitter or reddit. Just be polite and keep your head cool. They're people too. Try to imagine how you'd like to be approached when something you made doesn't work for somebody ;)
I solved by creating a stored procedure then passing the values to a json object. Created a trigger on Insert then execute the procedure. In my app it detects the source with switch case. I followed some examples and implemented to my needs.
It's telling that the majority of the code examples in that PDF are in Visual Basic, and C++ is treated as a 2nd class citizen in it :-(
The 2nd method (dumpcpp with only an .h) is at least technology from this century so I understand why you prefer it.
Try to see if there's a pattern to the SEG faults, perhaps there's some extra initialization you need to do due to that missing staticMetaObject.
The IDispatch errors are a symptom of inconsistencies in the .tlb file but are glossed over by Visual Basic and C#, but I think they can be fixed with some type coercing, e.g. static_cast<IDispatch*>(ptr)
P.S. There might actually be a 4th alternative, especially if you're only using a subset of that Robot library:
write a "wrapper" COM .dll in C#, I think it's called a CCW (Com Callable Wraper) that exports the stuff you want in a more modern way, which then can be consumed by Qt C++.
Side note for posterity, but I think I found a way to go about it which works better for me and doesn't involve messing around with MSVC.
For whatever reason, downloading the full Pylon SDK package with the viewer and everything doesn't work very well for me and doesn't let the cameras be recognised as such by my device.
However, if I use only a runtime (I used v5.2, but you could probably use a different one too), it works and gets recognised. QCamera now also recognises the camera, though it fails to set proper viewfinder settings and therefore doesn't work. It also finds 4 cameras instead of just one, which I think is a quirk of the driver or something, since OpenCV does the same thing. I would prefer to do everything with Qt and not be dependent on any external framework, so if there's any pointers on how to set proper viewfinder settings that would be much appreciated, but for now this is fine.
What works and does recognise the camera while reading properly from the camera is OpenCV. In order to be used with MinGW, it has to be made from source with make, but I've managed to make it work on my machine. I followed this guide on the subject, and it worked for me after restarting.
Anyway, I finally have something I can work on again, and I'll consider this question solved. Thanks for the help.
@SGaist, Ok, I think I get where you're both going now. I should have a Database handler class with separate queries for reading and writing each table. No need to over-complicate it by trying to abstract the queries themselves. If I'm honest with myself, I'm probably trying to do that because SQL is like that cute girl in high school who intimidates you a little bit. You're a little afraid to talk to her, and if you do work up the courage, you want to get as much done in that one conversation as possible. :-)
@bondrusiek said in Zlib library error | undefinied reference to:
when I use function from zlib like gzopen Compilator gives error message:
undefined reference to 'gzopen'
It's the linker complaining indeed...
Are you sure you have the shared object for Qt zlib library available?
How do you install Qt framework? Is it configured for -qt-zlib? See documentation regarding 3rd party libraries