C++ GUI Programming

[Mike_m]

I am new to Qt programming, with good understanding of C++.
I bought Prentice Hall Book, "C++ GUI Programming with Qt 4, Second Edition" by Blanchette and Summerfield. (2008 Published)
I have downloaded this books source code files from the book publisher's web site.

I have downloaded and installed on Windows, latest trial version of Qt free for about one month.

Following is above book's first program:

// hello.cpp
#include <QApplication>
#include <QLabel>

int main(int argc, char *argv[])
{
QApplication app(argc, argv);
QLabel *label = new QLabel("Hello Qt!");
label->show();
return app.exec();
}

Qt is saying No such file or directory for both QApplication and QLabel

Is there a way to fix above program, build and run please?

This book has many excellent Qt programming chapters. I like to be able to load the projects from this book into Qt Creator practice the Qt concepts please
Thanks,
Mike

[Santosh Reddy]

How did you install QtCreator, stand alone installer or from the Qt installation, or some other way ?

[Mike_m]

Installed using Qt installation. Thanks.

---

Added after 7 minutes:

I searched for QAapplication file on my Windows computer C drive and found following path for the QApplication include file:
C:\Qt\5.9\mingw53_32\include\QtWidgets

I am trying to add this folder path to the include path in Qt.
How to add (menu, sub-menu selections?) this QtWidgets include path please?

[Santosh Reddy]

Can you show the "QT" variable assignments in project file i.e. the .pro file.

[Mike_m]

I have hello.pro file and it has only following two lines:
TEMPLATE = app
SOURCES = hello.cpp

[Lesiok]

Start new project in Qt Creator with wizard. Then look in the created PRO file.

[Mike_m]

I ran qmake command and now I have following lines in hello.pro
TEMPLATE = app
TARGET = hello
INCLUDEPATH += .

Can I manually add my QApplication path to above INCLUDEPATH line?

[Santosh Reddy]

No.

Here try this.
https://wiki.qt.io/Basic_Qt_Programm..._a_new_project

[d_stranz]

I bought Prentice Hall Book, "C++ GUI Programming with Qt 4, Second Edition" by Blanchette and Summerfield. (2008 Published)

Be aware that between Qt4 (for which this book was written) and Qt5 (which you are presumably using), the locations of Qt header files and almost the entire Qt source tree layout changed completely. In addition, there are some argument changes to some very basic classes and methods. So examples from Blanchette and Summerfield's book will probably not immediately compile from the downloaded source. The book is otherwise a great way to learn the basics of the C++ side Qt.

Normally, you do not need to add explicit paths to Qt header files to the .pro file - when you "configure" the project with the correct "kit" in Qt Creator, it will set up the build environment to automatically find what it needs. The INCLUDEPATH directive in the .pro file is usually used for non-Qt headers, like those from external libraries.