I created a console application and have put this line in the .pro file:
CONFIG += c++11
Problem: if I use, for instance, std::to_string() in main.cpp, I have no problem, but if I create a new file/class (with QtCreator IDE) and I put to_string() in the class then I have a error that says that I have to use C++11. So it seems like the C++11 option only applies to main.cpp.
What could be the cause of this?
If I include(someOtherProject.pri) in my .pro, and that other project file (.pri) has INCLUDEPATH += . in it, then shouldn't my files in my .pro find those headers when I #include them? I cleaned and ran qmake on everything, regenerated the .pri file by simply copying the .pro from that other project and renaming it with the .pri extension, but when I #include a file from that other project, compiler says it cannot find it.
I wouldn't expect that I must also edit the INCLUDEPATH of my working .pro file if I am already using include(someOtherProject.pri) -- that would make the point of using include(someOtherProject.pri) unnecessary altogether.
The solution is to have INCLUDE PATH += $$PWD/ in the .pri instead, as this will expand out to the proper hard-coded path no matter where it is included.
I've got a problem with include in a qmake project. In my .pro file I've got:
INCLUDEPATH += "C:\OpenCV\build\include"
and in my cpp :
#include <opencv\cv.h>
The compiler indicates an error:
Cannot open include file: 'opencv\cv.h': No such file or directory
but if I write this in my cpp:
#include "C:\OpenCV\build\include\opencv\cv.h"
it works!
I build the project from within Qt Creator. What am I doing wrong?
You have to run qmake(build->run qmake) to validate changes in the pro file.
Qt creator Adding external library (still: Cannot open include file: 'GL/glew.h')
Your problem may be related to the fact that having backslashes in naked #include directives is undefined behavior.
Do the following.
Replace your include with
#include <opencv/cv.h>
Note the forward slash!
Remove the shadow build directory that Qt Creator has made for you. You will find it above the project directory, its name begins with build-.
Rebuild the project.
Note that this takes care of rerunning qmake.
here's one of my pro files:
# Blah Application
TEMPLATE = app
CONFIG += qt console staticlib debug_and_release
QT -= gui
QT += network sql xml
TARGET = blah
CONFIG(debug, debug|release){
DESTDIR = debug
LIBS += -L../../../lib/core/debug -lcore
} else {
DESTDIR = release
LIBS += -L../../../lib/core/release -lcore
}
DEPENDPATH += . ../../lib ../../../lib/core
INCLUDEPATH += . ../../lib ../../../lib/core
# Library files
HEADERS += mtBlahRTP.h
SOURCES += mtBlahRTP.cpp
# Input
HEADERS +=
SOURCES += main.cpp
The include path points to the RELATIVE directory of my lib files. mtBlahRTP.h and mtBlahRTP.cpp are in ../../lib
I have the same question, before building or running, you should qmake(Build=>qmake) it.
My configurations for INCLUDEPATH:
INCLUDEPATH+=D:\opencv\opencv\build\include
INCLUDEPATH+=D:\opencv\opencv\build\include\opencv
INCLUDEPATH+=D:\opencv\opencv\build\include\opencv2
I ran into a similar issue and what I found is that the QtCreator IDE is not re-reading the results of qmake and updating the "Cannot open" message. You need to close the offending file and re-open it - then you'll see that it no longer displays the error.
I had to do two steps: (re-)run qmake and rebuild the whole project - only then the INCLUDEPATH setting was considered correctly. (With QtCreator 3.5 and 3.6 (Qt 5.5 and Qt 5.6) on Windows.)
The only problem you are making is incorrectly linking the OpenCV library. The other answers given here may or may not work, but I have posted on another thread a surefire way to solve this problem using the "Add Library" wizard inside Qt Creator: https://stackoverflow.com/a/51914928/10245006
I was getting the error:
canserialcomm.o: In function `CanSerialComm::CanSerialComm()':
canserialcomm.cpp:(.text+0xc1): undefined reference to `vtable for CanSerialComm'
It turns out that the cause was it wasn't able to find canserialcomm.h where that constructor is declared. This was despite me having INCLUDEPATH in the project file point to the directory containing that header file:
INCLUDEPATH += . \
..
What I had to do to fix this is explicitely specify the header file; I added:
HEADER += ../canserialcomm.h
You should use double backslashes when in windows for qt creator with msvc. like this:
INCLUDEPATH += C:\\libcurl\\libcurl-vc-x64-release-dll-ipv6-sspi-winssl\\include
this will fix the problem.
Under windows you have to eliminate the -I before each directory that is added into the INCLUDEPATH variable.
For example:
Under windows:
INCLUDEPATH += "C:\lib\boost_1_61_0" (back-slash)
Under linux & mac:
INCLUDEPATH += -I"$$(HOME)/lib/boost_1_61_0" (note the -I and forward-slash)
I'm not sure whether it depends on different qmake version or not. But after finishing qmake command, I check the Makefile and the double -I is the issue.
You need to do several things. Fist, in the .pro file, you need quotation marks two backslashes at a time, like this:
INCLUDEPATH += "C:\\OpenCV\\build\\include\\opencv\\cv.h"
You alse need a frontslash in the #include in your .cpp file like this:
#include <opencv/cv.h>
When you've done this, delete the build folder. This is the folder with a very complicated name of the type build-untitled-Desktop_Qt_5_7_0_MSVC2015_32bit-Release. Then, in the Build menu, press "Run qmake". When you've done all this, it should compile fine.
Somehow it did not work for when I had several INCLUDEPATH +=.
When I combined the stuff into a single on it suddenly worked.
I made a custom library and i compiled it into a dll (qustom.dll).
Now i want to compile another project using this dll.
What i did is to import the header files in the project and add this line in my .pro file
LIBS += -lqustom
but i get "error: cannot find -lqustom"
also i tried
LIBS += qustom.dll
and
LIBS += -libqustom.a
qustom.dll is in the project directory
Also i tried
OTHER_FILES += \
qextserialport1.dll
but didn't work either
Am i missing something here?
Missing a path perhaps? -L/path/to/dlls -ldllname
Qt plays nicely with CMake. I use that and I never get dependency/path headaches like this any more.
I want to use CTelephony API in Qt Symbian project but after including etel3rdparty.h and etel3rdparty.lib as library and header in .pro file like this:
LIBS += C:/NokiaQtSDK/Symbian/SDK/epoc32/release/armv5/lib/etel3rdparty.lib
INCLUDEPATH += C:/NokiaQtSDK/Symbian/SDK/epoc32/include
I am getting a lot of compilation errors.
Please share if someone faced and find the solution of this problem.
You are not supposed to include each library with the complete path in the .pro file. You need only the name of the lib, without the extension, prefixed with -l, i.e. in your case
LIBS += -letel3rdparty
Also, you would normally not need to add epoc32\include to the include path, as it's added by default.