Qt auto generated form provides wrong path to source code files - c++

Question

I have added qcustomplot.h/.c files to my Qt project. They are located in: "QT_PROJECT_DIR/QCustomPlot/".
Every time I use the designer in Qt Creator and build I get this error in ui_mainwindow.h:
error: ../../qcustomplot.h: No such file or directory
#include "../../qcustomplot.h"
This is of course true as it is located in: "QT_PROJECT_DIR/QCustomPlot/"
How do I change how Qt Designer auto generate this path?
If it helps, here is my .pro:
#-------------------------------------------------
#
# Project created by QtCreator 2014-01-12T00:44:44
#
#-------------------------------------------------
QT += core gui
greaterThan(QT_MAJOR_VERSION, 4): QT += widgets widgets opengl printsupport
TARGET = Test
TEMPLATE = app
SOURCES += main.cpp\
mainwindow.cpp \
QCustomPlot/qcustomplot.cpp
HEADERS += mainwindow.h \
QCustomPlot/qcustomplot.h
FORMS += mainwindow.ui
CONFIG += mobility
MOBILITY =

Answer 1

Your include seems to be wrong:
#include "../../qcustomplot.h"
Since you do not add the QCustomPlot folder to your INCLUDEPATH, you would need to include the file as follows:
#include "QCustomPlot/qcustomplot.h"
Alternatively, you could change the INCLUDEPATH as follows:
INCLUDEPATH += $$QT_PROJECT_DIR/QCustomPlot/
and then you could include the header without the ugly ../../ relative reference as follows:
#include "qcustomplot.h"
It is a rule of thumb to avoid such relative include paths in the source and headers files themselves because the structure can change at any time, or may be different on a different machine, et al. It is better resolved by the buildsystem and include paths.

Answer 2

I met the same problem and have solved it.
It was caused by the path of qcustomplot object in xxx.ui.
Step 1: Open the ***.ui file which contains the qcustomplot item.
Step 2: Right click the qcustomplot item
Step 3: Double click the path of QCustomPlot, then change it to QCustomPlot/qcustomplot.cpp from ../../customplot.
Finally, the header of ui_***.h can auto include QCustomPlot/qcustomplot.cpp, instead of ../../qcustomplot.h.
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