QT learning 04 Hello QT

Qt Study 04 Hello Qt

Qt What is it? ？

• Qt It's a set Cross platform Of GUI Development Library
• Qt It's a set C++ Inherit the development environment
• Qt It's a set Open source palace level architecture technology tutorial

Get into Qt The world of

• first Qt Program

#include <QApplication>
#include <QMainWindow>
#include <QPushButton>

int main(int argc, char *argv[])
{
    
    QApplication a(argc, arv);
    QMainWindow w;
    QPushButton b(&w);
    
    b.setText("Hello QT!");
    w.show();
    return a.exec();
}

Qt development environment

• adopt Command line The way to compile Qt Source program
• start-up Qt Command line
• Enter the directory where the source program is located
• command ：
  1.qmake -project // Generate project files according to the source code in the directory
  2.qmake // According to the project file generation makefile file
  3.make // according to makefile Compile

Qt Creator

• Qt Creator It's a set Visual integrated development environment
• Use Qt Creator Sure efficient Conduct Qt Development
• Qt Creator Provides Powerful code editing function
• Qt Creator Provides Powerful debugging function

The basic method of debugging

• Log Debugging method ：

  Add some... To the code Print statement

  Print Program status and Key variables Value

• Breakpoint debugging

  Add... To the corresponding line of code in the development environment The breakpoint

  When the program runs to the breakpoint line , The program stops running

  Add... If necessary Conditional breakpoints , When the conditions are met, the program will be suspended

Summary

• Qt One set per hour Cross platform Of C++ Interface development library
• Can pass Command line Way of development Qt Applications
• It can also be done through Qt Creator Conduct Qt Development
• Qt Creator Support at the same time Log Debugging method and Breakpoint debugging