I have to subclass QApplication and redefine event function, that waiting for FileOpen event and runs some actions after it comes, and also i created template Info.plist file with extensions of registred filetypes for this application. When i try to open associated file by double mouse click, application have to start and creates main window, but then it crash in QCoreApplication::Arguments and message box from Application::event not executed.

Qt Code: 
  1. class Application : QApplication
  2. {
  3. public:
  4.    Application( int argc, char * argv[]):QApplication(argc,argv){}
  5. protected:
  6.    virtual bool event(QEvent * event )
  7. {
  8.    if( event->type() == QEvent::FileOpen )
  9.    {
  11.       box.setText(static_cast<QFileOpenEvent>(event)->file());
  12.       box.exec();
  13.       return true;
  14.    }
  15.    return false;
  16. }
  17.  
  18. }
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But if i create messagebox before event type check(as in code below), it works fine, both messagebox are showing. What could be the the reason for this behavior ?

Qt Code: 
  1. class Application : QApplication
  2. {
  3. public:
  4.    Application( int argc, char * argv[]):QApplication(argc,argv){}
  5. protected:
  6.    virtual bool event(QEvent * event )
  7. {
  8.    QMessageBox msgbox;
  9.    msgbox.setText(QString::number(event->type()));
  10.    msgbox.exec()
  11.    if( event->type() == QEvent::FileOpen )
  12.    {
  14.       box.setText(static_cast<QFileOpenEvent>(event)->file());
  15.       box.exec();
  16.       return true;
  17.    }
  18.    return false;
  19. }
  20.  
  21. }
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