Change Screen Resolution

Question

I've got a problem. I need to change screen resolution inside of my QT Project(like in some games for example). I have heard that I need to use Windows API, like following:

DEVMODE devmode;
devmode.dmPelsWidth = 1024;
devmode.dmPelsHeight = 768;
devmode.dmFields = DM_PELSWIDTH | DM_PELSHEIGHT;
devmode.dmSize = sizeof(DEVMODE);

long result = ChangeDisplaySettings(&devmode, 0);
qDebug() << "RESULT OF CHANGE DISPLAY :"<< result;

But Qt says: "'DEVMODE': undeclared identifier". How can I fix it? Maybe I need to include some libraries?

Answer 1

You have to include windows.h header. Here is an working example.

#include <stdio.h>
#include <windows.h>
#include <winuser.h>

int main() {

    DEVMODE devmode;
    devmode.dmPelsWidth = 1024;
    devmode.dmPelsHeight = 768;
    devmode.dmFields = DM_PELSWIDTH | DM_PELSHEIGHT;
    devmode.dmSize = sizeof(DEVMODE);

    long result = ChangeDisplaySettings(&devmode, 0);

    return 0;
}