1. Practice Meet QT Creator.

Objective: create a new project Hello World

Performance:

1. Open QtCreator;
2. Go to File -> New File or Project;
3. Select the project type "Application" -> "Qt Widgets Application", press the Select button;
4. Name your project (for example, Hello world) and select the folder in which the project will be created, click Next;
5. Select the library bundle that fits your system (for example, Desktop Qt 5.3 MSVC2013 32bit), click Next;
   
6. Enter the class name (the name of the main form file) or leave the field unchanged (the standard class name mainwindow will be used later), click Next;
7. If you need version control and you have the appropriate utility installed, select it in the appropriate drop-down menu; click Finish;
8. Double-click to open the form file (mainwindow.ui);
9. Drag 2 Label objects (Display Widgets section) and 1 Push Button object (Buttons section) onto the form;
   
10. Select 1st TextLabel, double-click on the object to change its inscription to "Hello World";
11. In the properties of the object (lower right corner), QLabel section, change the textFormat property to RichText;
12. Click on the text property, a button will appear to the right of the text (...), click on it;
13. In the window that opens, select all the text, set its font size to 16, italics, click OK;
    
14. In the left pane, open the Editor, double-click to open the header file (mainwindow.h);
15. After the lines
    private:
    Ui :: MainWindow * ui;
    add the following line:
    private slots:
    void helloWorld ();
16. Open the mainwindow.cpp file and add the following code:
    1) after the line
    ui-> setupUi (this);
    add
    connect (ui-> pushButton, SIGNAL (clicked ()), this, SLOT (helloWorld ()));
    2) at the end of the file add the following code:
    void MainWindow :: helloWorld () {
    ui-> label_2-> setText ("World Hello");
    }
17. Run the project (button in the lower left corner, or Ctrl + R combination).

Result: