C++ Close window not application - c++

Question

I'm trying to create two instances of a window class.
When the primary one is closed it should close the application but when the secondary one is closed it should just close that window.
However when either window is closed the application exits, and I'm not sure why. I've tried comparing the hWnd to check which window is being closed.
// include the basic windows header file
#include <windows.h>
#include <windowsx.h>
//Forgive me now
#define MAX_WINDOWS 1024
HWND hWindows[MAX_WINDOWS];
// the WindowProc function prototype
LRESULT CALLBACK WindowProc(HWND hWnd,
UINT message,
WPARAM wParam,
LPARAM lParam);
// the entry point for any Windows program
int WINAPI WinMain(HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPSTR lpCmdLine,
int nCmdShow)
{
WNDCLASSEX wc;
ZeroMemory(&wc, sizeof(WNDCLASSEX));
wc.cbSize = sizeof(WNDCLASSEX);
wc.style = CS_HREDRAW | CS_VREDRAW;
wc.lpfnWndProc = WindowProc;
wc.hInstance = hInstance;
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH)COLOR_WINDOW;
wc.lpszClassName = L"WindowClass1";
RegisterClassEx(&wc);
hWindows[0] = CreateWindowEx(NULL,
L"WindowClass1", // name of the window class
L"Our First Windowed Program", // title of the window
WS_OVERLAPPEDWINDOW, // window style
300, // x-position of the window
300, // y-position of the window
500, // width of the window
400, // height of the window
NULL, // we have no parent window, NULL
NULL, // we aren't using menus, NULL
hInstance, // application handle
NULL); // used with multiple windows, NULL
hWindows[1] = CreateWindowEx(NULL,
L"WindowClass1", // name of the window class
L"Our First Windowed Program", // title of the window
WS_OVERLAPPEDWINDOW, // window style
300, // x-position of the window
300, // y-position of the window
500, // width of the window
400, // height of the window
hWindows[0], // primary window
NULL, // we aren't using menus, NULL
hInstance, // application handle
NULL); // used with multiple windows, NULL
ShowWindow(hWindows[0], nCmdShow);
ShowWindow(hWindows[1], nCmdShow);
MSG msg;
while (GetMessage(&msg, NULL, 0, 0))
{
// translate keystroke messages into the right format
TranslateMessage(&msg);
// send the message to the WindowProc function
DispatchMessage(&msg);
}
// return this part of the WM_QUIT message to Windows
return msg.wParam;
}
// this is the main message handler for the program
LRESULT CALLBACK WindowProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
// sort through and find what code to run for the message given
switch (message)
{
case WM_CLOSE:
{
if (hWnd = hWindows[0]) {
// close the application entirely
PostQuitMessage(0);
}
else {
DestroyWindow(hWnd);
}
return 0;
} break;
}
// Handle any messages the switch statement didn't
return DefWindowProc(hWnd, message, wParam, lParam);
}

Answer 1

if (hWnd = hWindows[0])
That's assignment. Since hWindows[0] is non-zero, that expression always evaluates true.
You mean:
if (hWnd == hWindows[0])
You should call PostQuitMessage in response to WM_DESTROY. And since the default window procedure calls DestroyWindow in response to WM_CLOSE, you can write it like this:
switch (message)
{
case WM_DESTROY:
{
if (hWnd == hWindows[0]) {
// close the application entirely
PostQuitMessage(0);
}
return 0;
}
break;
}
// Handle any messages the switch statement didn't
return DefWindowProc(hWnd, message, wParam, lParam);