C++ GUI Programming with Qt 3

Chapter 1. Getting Started

• Hello Qt

• Making Connections

• Using the Reference Documentation

This chapter shows how to combine basic C++ with the functionality provided by Qt to create a few small graphical user interface (GUI) applications. This chapter also introduces two key Qt ideas: “signals and slots” and layouts. In Chapter 2, we will go into more depth, and in Chapter 3, we will start building a realistic application.

Hello Qt

Here’s a very simple Qt program:

 1 #include <qapplication.h>
 2 #include <qlabel.h>

 3 int main(int argc, char *argv[])
 4 {
 5     QApplication app (argc, argv);
 6     QLabel *label = new QLabel("Hello Qt!", 0);
 7     app.setMainWidget(label);
 8     label->show();
 9     return app.exec();
10 }

We will first study it line by line, then we will see ...