Qapplication::alert If the window is not the active window, a warning is displayed to the window (very useful, as is the case with TeamViewer)

void Qapplication::alert (Qwidget * widget, int msec = 0)
If the window is not the active window, a warning is displayed to the window. The alert will display msec milliseconds.
If the millisecond is zero, the blink will stop after a period of time, and the taskbar icon will remain lit.

Widget.h

2. #ifndef Widget_h
4. #define Widget_h
8. #include <QWidget>
10. #include <QTimer>
12. #include <QTime>
14. Namespace Ui {
16. Class Widget;
18. }
22. Class Widget:public Qwidget
24. {
26. Q_object
30. Public
32. Explicit Widget (Qwidget *parent = 0);
34. ~widget ();
38. void Setms (int m);
42. Public Slots:
44. void Start ();
48. Private
50. Ui::widget *ui;
52. int MS;
54. Qtimer *timer;
56. };
60. #endif//Widget_h

Widget.cpp

2. #include "Widget.h"
4. #include "Ui_widget.h"
8. Widget::widget (Qwidget *parent):
10. Qwidget (parent),
12. UI (New Ui::widget)
14. {
16. UI->SETUPUI (this);
20. Timer = new Qtimer ();
22. Timer->setinterval (1000);
24. Timer->start ();
28. Connect (timer, SIGNAL (), this, SLOT (Start ()));
30. }
34. Widget::~widget ()
36. {
38. Delete UI;
40. }
44. void Widget::start ()
46. {
48. Qapplication::alert (this, MS);
50. }
56. void Widget::setms (int m)
58. {
60. Ms=m;
62. }

Main.cpp

1. #include "Widget.h"
2. #include <QApplication>
3. int main (int argc, char *argv[])
4. {
5. Qapplication A (argc, argv);
6. Widget W;
7. W.SETMS (1000);
8. W.show ();
10. return A.exec ();
11. }

Http://blog.chinaunix.net/uid-29994589-id-5207150.html

Qapplication::alert If the window is not the active window, a warning is displayed to the window (very useful, as is the case with TeamViewer)