How to change windows system time in Qt? - c++

Question

I want to change my system time ,How can I change the Windows system time in Qt?
I used this way,but failed!
#include <QApplication>
#include <iostream>
#include <time.h>
#include <windows.h>
#include <QDateTime>
#include <QDebug>
using namespace std;
bool setDate(int,int,int);
int main(int argc, char *argv[])
{
QApplication a(argc, argv);
MainWindow w;
w.show();
qDebug()<<QDateTime::currentDateTime()<<endl; //before change time
if(setDate(2015,1,1)) //set time
{
qDebug()<<QDateTime::currentDateTime()<<endl; //if succeed,output time
}
return a.exec();
}
bool setDate(int year,int mon,int day)
{
SYSTEMTIME st;
GetSystemTime(&st); // Win32 API get time
st.wYear=year; //set year
st.wMonth=mon; //set month
st.wDay=day; //set day
return SetSystemTime(&st); //Win32 API set time
}
Thank you in advance.

Answer 1

Changing the system time requires admin rights. That means you need to:
Add the requireAdministrator option to your manifest so that the program always has admin rights. That's a bad idea and you won't enjoy the UAC dialog every time you start.
Or, change the time by starting a separate process that runs as administrator. Another executable with the appropriate manifest, a process started with the runas shell verb, or one started with the COM elevation moniker.
If this is gobbledygook to you, you need to read up on UAC. Start here: https://msdn.microsoft.com/en-us/library/windows/desktop/dn742497(v=vs.85).aspx