Book Image

Cross-Platform Development with Qt 6 and Modern C++

By : Nibedit Dey
Book Image

Cross-Platform Development with Qt 6 and Modern C++

By: Nibedit Dey

Overview of this book

Qt is a cross-platform application development framework widely used for developing applications that can run on a wide range of hardware platforms with little to no change in the underlying codebase. If you have basic knowledge of C++ and want to build desktop or mobile applications with a modern graphical user interface (GUI), Qt is the right choice for you. Cross-Platform Development with Qt 6 and Modern C++ helps you understand why Qt is one of the favorite GUI frameworks adopted by industries worldwide, covering the essentials of programming GUI apps across a multitude of platforms using the standard C++17 and Qt 6 features. Starting with the fundamentals of the Qt framework, including the features offered by Qt Creator, this practical guide will show you how to create classic user interfaces using Qt Widgets and touch-friendly user interfaces using Qt Quick. As you advance, you'll explore the Qt Creator IDE for developing applications for multiple desktops as well as for embedded and mobile platforms. You will also learn advanced concepts about signals and slots. Finally, the book takes you through debugging and testing your app with Qt Creator IDE. By the end of this book, you'll be able to build cross-platform applications with a modern GUI along with the speed and power of native apps.
Table of Contents (17 chapters)
Section 1: The Basics
Section 2: Cross-Platform Development
Section 3: Advanced Programming, Debugging, and Deployment

Debugging a C++ application

The QDebug class can be used to print the value of a variable to the application output window. QDebug is similar to std::cout in the standard library, but it has the benefit of being part of Qt, which means it supports Qt classes out of the box and can display its value without the need for conversion.

To enable debugging messages, we must include the QDebug header as follows:

#include <QDebug>

Qt provides several global macros for generating different types of debug messages. They can be used for different purposes, mentioned as follows:

  • qDebug() provides a custom debug message.
  • qInfo() provides informational messages.
  • qWarning() reports warnings and recoverable errors.
  • qCritical() provides critical error messages and reports system errors.
  • qFatal() provides fatal error messages before exiting.

You can see if your feature is working correctly by using qDebug(). After you've finished looking for the error...