C++ runtime Error in Running Program

[ramin.lich]

hi all
this is Full Source of My Program

#include "mainwindow.h"
#include <QApplication>
#include <QSystemTrayIcon>
#include <QMenu>
#include <QAction>
#include <QFileDialog>
#include <QMessageBox>
#include <thread>
#include <fstream>
#include <QTextStream>
#include <time.h>
#include <windows.h>
using namespace std;



const tm* timeinfos;
void tray();
void refresh();
void starts();
void wait();
ofstream dif("d:\\dif.txt");
const char* const path = "d:\\dif.txt" ;
void starts();
int hour=0,minu=0;
ofstream times("d:\\time.txt");
struct tm * timeinfo;
time_t rawtime = time(0) ;
int sec,secd;
MainWindow w;



int main(int argc, char *argv[])
{
QApplication a(argc, argv);
w.hide();
std::thread first(tray);
std::thread second(starts);
std::thread third(refresh);
starts();
first.join();
third.join();

return a.exec();
}


void tray(){
QSystemTrayIcon *trayIcon=new QSystemTrayIcon();
QMenu *menu=new QMenu("TimeUsage");
menu->addAction("Open");
menu->addAction("Exit");
trayIcon->setContextMenu(menu);
trayIcon->setIcon(QIcon("e:\\icon.png"));
trayIcon->show();
trayIcon->showMessage("TimeUsage","TimeUsage Is Here!");

QObject::connect(menu,&QMenu::triggered,[&w](QAction* act){

const auto& text = act->text();
if(text=="Exit"){
QApplication::exit();
}
else if(text=="Open"){
w.show();
}


});
}


void refresh(){
for(;;){
wait();
time_t now = time(0) ;
ifstream dif(path);
time_t earlier = 0 ;
dif >> earlier ;

double secs = difftime( now, earlier );
minu=secs/60;
while(minu>60){
minu-=60;
hour++;
}
QFile times("d:\\time.txt");
times.open(QIODevice::Append);
QTextStream stream(&times);
stream<<asctime(timeinfos)<<endl<<hour<<"/"<<minu<<endl;
}
}


void starts(){
timeinfos = localtime ( &rawtime );

ofstream dif(path);
dif << rawtime << '\n' ;
dif.close();
refresh();
}


void wait(){
int i;
for (i=0; i<=10; ++i) {
this_thread::sleep_for (chrono::seconds(1));
}
}

the Program Has No Problem With Compiling But will Not Run And I Get the Following Error:
10612
Any Help Will Be Great

[faldzip]

1. You have to create QApplication before creating any widgets - if you must have this global variable MainWindow w; then make it a pointer and then allocate on a heap after QApplication creation.
2. But it is not going to work either as you cannot access the widgets from threads other than UI thread (which is the main thread).

[rezas1000]

this code is completely wrong. So what is the difference between Library of the console and The library of the desktop?