creating cpp library using qt
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#------------------------------------------------- # # Project created by QtCreator 2017-07-27T15:45:22 # #------------------------------------------------- QT += widgets QT -= core gui TARGET = worksharedlib TEMPLATE = lib DEFINES += WORKSHAREDLIB_LIBRARY SOURCES += worksharedlib.cpp HEADERS += worksharedlib.h\ worksharedlib_global.h unix { target.path = /usr/lib INSTALLS += target }sharedlib.h
#ifndef WORKSHAREDLIB_H #define WORKSHAREDLIB_H #include "worksharedlib_global.h" #include<qobject.h> #include<qwidget.h> #include <QPushButton> #include<QLineEdit> #include <QHBoxLayout> #include<qlabel.h> #include<QtGui> class WORKSHAREDLIBSHARED_EXPORT Worksharedlib:public QWidget { Q_OBJECT public: //Worksharedlib(); Worksharedlib(QWidget *parent = 0); ~Worksharedlib() {} private slots: void handleButton(); void m_buttonClicked(); private: QPushButton *m_button; QLineEdit *m_textbox; QHBoxLayout *layout; QWidget *window; QLabel * label; QWidget *frame; }; #endif // WORKSHAREDLIB_Hsharedlib_global.h
#ifndef WORKSHAREDLIB_GLOBAL_H #define WORKSHAREDLIB_GLOBAL_H #include <QtCore/qglobal.h> #if defined(WORKSHAREDLIB_LIBRARY) # define WORKSHAREDLIBSHARED_EXPORT Q_DECL_EXPORT #else # define WORKSHAREDLIBSHARED_EXPORT Q_DECL_IMPORT #endif #endif // WORKSHAREDLIB_GLOBAL_Hsharedlib.cpp
#include "worksharedlib.h" #include <QCoreApplication> #include <QMessageBox> #include <QDebug> using namespace std; Worksharedlib::Worksharedlib(QWidget *parent) : QWidget (parent) { layout = new QHBoxLayout( this ); m_textbox = new QLineEdit ( this ); // Create the button, make "this" the parent m_button = new QPushButton("My Button",this); // set size and location of the button m_button->setGeometry(QRect(QPoint(300, 200), QSize(200, 50))); //create the text box layout->addWidget(m_textbox); m_textbox->setGeometry(100,200,90,25); //try image //create a image viewer QString url = R"(/home/pi/krishna.jpg)"; QPixmap img(url); QLabel *label = new QLabel(this); label->setGeometry(200,300,100,50); label->resize(this->width(),300); label->setPixmap(img); // Connect button signal to appropriate slot connect(m_button, SIGNAL (clicked()), this, SLOT (m_buttonClicked())); } void Worksharedlib::m_buttonClicked() { m_textbox = new QLineEdit; m_textbox->setPlaceholderText("Placeholder Text"); m_textbox->setFocus(); QMessageBox::information( this, "Information", "Just clicked Ui PushButton" ); }in which all qt applications can i call this library.. what is the correct method to call this library in an application..
@amruz said in creating cpp library using qt:
in which all qt applications can i call this library.. what is the correct method to call this library in an application..
You just link against your library and Qt in your app.
See here http://doc.qt.io/qtcreator/creator-project-qmake-libraries.html -
@jsulm the pro file of my application which calls the library is
QT += core QT -= gui CONFIG += c++11 TARGET = testcretedlibrary CONFIG += console CONFIG -= app_bundle TEMPLATE = app SOURCES += main.cpp DEPENDPATH += /home/amruz/worksharedlib INCLUDEPATH += /home/amruz/worksharedlib LIBS += -L /home/amruz/build-worksharedlib-Desktop_Qt_5_7_0_GCC_64bit-Debug -lworksharedlib -
@jsulm the pro file of my application which calls the library is
QT += core QT -= gui CONFIG += c++11 TARGET = testcretedlibrary CONFIG += console CONFIG -= app_bundle TEMPLATE = app SOURCES += main.cpp DEPENDPATH += /home/amruz/worksharedlib INCLUDEPATH += /home/amruz/worksharedlib LIBS += -L /home/amruz/build-worksharedlib-Desktop_Qt_5_7_0_GCC_64bit-Debug -lworksharedlib -
@amruz Add
QT += widgetsFix the LIBS line (no space between -L and the path):
LIBS += -L/home/amruz/build-worksharedlib-Desktop_Qt_5_7_0_GCC_64bit-Debug -lworksharedlib -
@jsulm said in creating cpp library using qt:
QT += widgets
can you also help me in writing the main.cpp file..
how to actually call the mainwindow there with the library output in it@amruz You use it as any other library. You're already doing it with Qt.
Just include the header file of your library and use it. For example create an instance of Worksharedlib.#include "sharedlib.h" int main() { ... Worksharedlib lib; lib.show(); ... } -
@amruz You use it as any other library. You're already doing it with Qt.
Just include the header file of your library and use it. For example create an instance of Worksharedlib.#include "sharedlib.h" int main() { ... Worksharedlib lib; lib.show(); ... } -
@jsulm said in creating cpp library using qt:
Worksharedlib lib;
lib.show();i used the same way only.. but i am getting error as follows
/home/amruz/worksharedlib/worksharedlib.h:14: error: undefined reference to `vtable for Worksharedlib'
@amruz Will probably not solve that error, but this looks wrong as well:
QT -= guiYour app is going to show an UI, right? Then it is a gui app:
QT += core gui widgetsDon't forget to rerun qmake after changing pro file and rebuild.
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@amruz Will probably not solve that error, but this looks wrong as well:
QT -= guiYour app is going to show an UI, right? Then it is a gui app:
QT += core gui widgetsDon't forget to rerun qmake after changing pro file and rebuild.
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@jsulm said in creating cpp library using qt:
QT += core gui widgets
this is a console application actually..is that the problem?
@amruz If it is a console application then why do you want to use a library which provides an UI class:
class WORKSHAREDLIBSHARED_EXPORT Worksharedlib:public QWidget { Q_OBJECT public: //Worksharedlib(); Worksharedlib(QWidget *parent = 0); ~Worksharedlib() {} private slots: void handleButton(); void m_buttonClicked(); private: QPushButton *m_button; QLineEdit *m_textbox; QHBoxLayout *layout; QWidget *window; QLabel * label; QWidget *frame; };?
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@amruz If it is a console application then why do you want to use a library which provides an UI class:
class WORKSHAREDLIBSHARED_EXPORT Worksharedlib:public QWidget { Q_OBJECT public: //Worksharedlib(); Worksharedlib(QWidget *parent = 0); ~Worksharedlib() {} private slots: void handleButton(); void m_buttonClicked(); private: QPushButton *m_button; QLineEdit *m_textbox; QHBoxLayout *layout; QWidget *window; QLabel * label; QWidget *frame; };?
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@amruz Yes. You're using widgets - so it must be a gui application with widgets, right?
QT += core gui widgets@jsulm when i try to include this library in a widget application also i am getting the same error..
this is the .pro file of my widgetapplication
#------------------------------------------------- # # Project created by QtCreator 2017-07-27T17:19:21 # #------------------------------------------------- QT += core gui widgets greaterThan(QT_MAJOR_VERSION, 4): QT += widgets TARGET = sharedlibtryinwidget TEMPLATE = app SOURCES += main.cpp\ mainwindow.cpp HEADERS += mainwindow.h DEPENDPATH += /home/amruz/worksharedlib INCLUDEPATH += /home/amruz/worksharedlib LIBS += -L/home/amruz/build-worksharedlib-Desktop_Qt_5_7_0_GCC_64bit-Debug -lworksharedlib -
@jsulm when i try to include this library in a widget application also i am getting the same error..
this is the .pro file of my widgetapplication
#------------------------------------------------- # # Project created by QtCreator 2017-07-27T17:19:21 # #------------------------------------------------- QT += core gui widgets greaterThan(QT_MAJOR_VERSION, 4): QT += widgets TARGET = sharedlibtryinwidget TEMPLATE = app SOURCES += main.cpp\ mainwindow.cpp HEADERS += mainwindow.h DEPENDPATH += /home/amruz/worksharedlib INCLUDEPATH += /home/amruz/worksharedlib LIBS += -L/home/amruz/build-worksharedlib-Desktop_Qt_5_7_0_GCC_64bit-Debug -lworksharedlib -
@amruz Yes. You're using widgets - so it must be a gui application with widgets, right?
QT += core gui widgets
