如何在循环中运行 qt 主 window 避免 Qt app.exec() 阻塞主线程

Question

I'm new to Qt, but need to solve a difficult problem.

Need to run qt main window in loop, in which app.exec() will blocking main function until exit is received. but i want to show and hide the main window in loop based on the events received to hide and show the main window

here is sample code now i'm using example:

void main(int argc, char **argv)
{
  //QT window init
  w.setVisible(true);
  app.exec();
}

Can call time init of qt window and do hide and show in loop?

I need to add while loop, on based on events hide or show main window will show and hide

void main(int argc, char **argv)
{
  //QT window init
  w.setVisible(true);
  app.exec();
  while(1)
 {
  //if show status received 
    if(show)
     w.setVisible(true);
  // if hide window status received 
   else if(hide)
     w.setVisible(false);
 }
}

how to keep app.exe alive all the time to achieve hide/show of window? any other QT api call?

i have gone through this link

Answer 1

Qt's recommended solution for this case is to add a QTimer and set the timeout to zero, which will guarantee that your callback gets called in every loop.

To make your application perform idle processing, ie, executing a special function whenever there are no pending events, use a QTimer with 0 timeout. More advanced idle processing schemes can be achieved using processEvents().

https://doc.qt.io/qt-5/qapplication.html#exec

You could go the brave way to subclass QApplication and copy/paste the source of exec() but I'd strongly recommend against that as the preparation and cleanup code in there can change at any new release.