I am designing Qt log window, So I am using qInstallMsgHandler() function to log all the debug, critical & warning messages on to QTableWidget (in below code I have not implemented It yet). I did as below

Qt Code: 
  1. int main(int argc, char *argv[])
  2. {
  3.     qInstallMsgHandler(MainWindow::logMessage);
  4.     //qInstallMsgHandler(&MainWindow::logMessage);  //I tried this also
  5.  
  6.     QApplication a(argc, argv);
  7.     MainWindow w;
  8.     qDebug()    << "info message";
  9.     qWarning()  << "warning message";
  10.     qCritical() << "critical message";
  11.     w.show();
  12.  
  13.     return a.exec();
  14. }
To copy to clipboard, switch view to plain text mode 

MainWindow:

Qt Code: 
  1. MainWindow::MainWindow(QWidget *parent) :QMainWindow(parent),ui(new Ui::MainWindow)
  2. {
  3.     ui->setupUi(this);
  4. }
  5.  
  6. MainWindow::~MainWindow()
  7. {
  8.     delete ui;
  9. }
  10.  
  11. void MainWindow::logMessage(QtMsgType type, const char *msg)
  12. {
  13.     switch (type) 
  14.    {
  15.     case QtDebugMsg:
  16.         fprintf(stderr, "Debug: %s\n", msg);
  17.         break;
  18.     case QtWarningMsg:
  19.         fprintf(stderr, "Warning: %s\n", msg);
  20.         break;
  21.     case QtCriticalMsg:
  22.         fprintf(stderr, "Critical: %s\n", msg);
  23.         break;
  24.     case QtFatalMsg:
  25.         fprintf(stderr, "Fatal: %s\n", msg);
  26.         abort();
  27.     }
  28. }
To copy to clipboard, switch view to plain text mode 

When I compile this code, I am getting below error

Qt Code: 
  1. main.cpp:27: error: cannot convert 'void (MainWindow::*)(QtMsgType, const char*)' to 'QtMsgHandler {aka void (*)(QtMsgType, const char*)}' for argument '1' to 'void (* qInstallMsgHandler(QtMsgHandler))(QtMsgType, const char*)'
  2.      qInstallMsgHandler(MainWindow::logMessage);
To copy to clipboard, switch view to plain text mode 

Note : If I changed void MainWindow::logMessage(QtMsgType type, const char *msg); this function to static function then it is working fine.
(But if this function is static, I can not create QTableWidgetItem and add them to tableWidget so I want this function to be non static).

And one more issue i am having here, When I use static function, all the messages are printing after I close my application only.

Please let me know What is the issue.

I am using Qt4.8.6 on Windows7

Thanks In Advance.