Here are the steps to display an active Font Combo Box widget and to apply the selected font to the text written in the Text Edit widget:
- Create a new application of the Dialog without Buttons template and drag two Label widgets, a Font Combo Box widget, and a Text Edit widget from the Widget box and drop them onto the form.
- Set the text property of the first Label widget to Select desired font and that of the second Label widget to Type some text.
- Save the application by name as demoFontComboBox.ui. The form will now appear as shown in the following screenshot:

The user interface created with Qt Designer is stored in a .ui ...