QT -- create QT program

New folder -- Chinese path is not required

open qt 

  Example ： It's a self-contained example

 

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  Start to practice -- Create a new one qt

  Click on choose

  You can choose multiple or single -- next step

  Base class ：QMainwindow  stay pc End windows window , With menu bar

Qdialog: Dialog box

qwidget： The most commonly used base class

Change to ： amount to Class name is a subclass Base class ： Parent class

That is ： class myWidget:public QWidget

Click next complete  

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  Realization effect ：

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Three ways to run  

 

  Shortcut key ctrl+r

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function ： Realization effect

  How to look at the code

 

  A program from main The function starts to see ：

 

#include "mywidget.h"
#include <QApplication>
//QApplication Application class 
//Qt The header file doesn't have .h
// The header file is the same as the class name 
// The header file is capitalized with the first two letters 

int main(int argc, char *argv[])
{
    // Objects with and only one application class --- Even if there are many windows 
    QApplication a(argc, argv);
    //myWidget  Inherited from QWidget,QWidget Is a window base class 
    // therefore myWidget It is also a window class 
    //w It's just a window   Instance object 
    myWidget w;
    // Window creation is hidden by default , It needs to be displayed manually 
    w.show();
    // These two sentences are equivalent to the following sentence 
    //a.exec(); a Is the application window created earlier   Keep the program running , Waiting for user operation , Cycle all the time  
    // And wait for the event to happen （ Mouse events   The occurrence of keyboard events ）
    //return 0;
    return a.exec();
}

Constructors Destructor  

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  Go to the project file to check ：

 

stay explorer It shows that

  after

 

 

 

The meaning of the module ： Go to .h In file , Place the cursor in the base class Press F1 Enter the help document