How To Get The Screen Resolution In Pixels

The function GetWindowRect(), defined in WinUser.h, is able to give the current screen resolution. The declaration of GetWindowRect() is

BOOL
WINAPI
GetWindowRect(
    __in HWND hWnd,
    __out LPRECT lpRect);

We can give a handle to the current desktop window to the above function as input. A sample implementation for getting the current screen resolution is given below.

#include "wtypes.h"
#include <iostream>
using namespace std;

// Get the horizontal and vertical screen sizes in pixel
void GetDesktopResolution(int& horizontal, int& vertical)
{
   RECT desktop;
   // Get a handle to the desktop window
   const HWND hDesktop = GetDesktopWindow();
   // Get the size of screen to the variable desktop
   GetWindowRect(hDesktop, &desktop);
   // The top left corner will have coordinates (0,0)
   // and the bottom right corner will have coordinates
   // (horizontal, vertical)
   horizontal = desktop.right;
   vertical = desktop.bottom;
}

int main()
{       
   int horizontal = 0;
   int vertical = 0;
   GetDesktopResolution(horizontal, vertical);
   cout << horizontal << '\n' << vertical << '\n';
   return 0;
}