Passing an HINSTANCE to WNDCLASS using the main entry point - c

Question

Consider the following code:
#include <windows.h>
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
PWSTR pCmdLine, int nCmdShow) {
MSG msg;
HWND hwnd;
WNDCLASSW wc;
wc.style = CS_HREDRAW | CS_VREDRAW;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.lpszClassName = L"Window";
wc.hInstance = hInstance;
wc.hbrBackground = GetSysColorBrush(COLOR_3DFACE);
wc.lpszMenuName = NULL;
wc.lpfnWndProc = WndProc;
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
RegisterClassW(&wc);
hwnd = CreateWindowW(wc.lpszClassName, L"Window",
WS_OVERLAPPEDWINDOW | WS_VISIBLE,
100, 100, 350, 250, NULL, NULL, hInstance, NULL);
ShowWindow(hwnd, nCmdShow);
UpdateWindow(hwnd);
while (GetMessage(&msg, NULL, 0, 0)) {
DispatchMessage(&msg);
}
return (int) msg.wParam;
}
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg,
WPARAM wParam, LPARAM lParam) {
switch(msg) {
case WM_DESTROY:
PostQuitMessage(0);
break;
}
return DefWindowProcW(hwnd, msg, wParam, lParam);
}
This creates a blank window, I want to reproduce this but using the main entry point instead of wWinMain.
The following code works, but it feels very hacky:
#include <windows.h>
LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
int main(int argc, HINSTANCE argv) {
MSG msg;
HWND hwnd;
WNDCLASSW wc;
wc.style = CS_HREDRAW | CS_VREDRAW;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.lpszClassName = L"Window";
wc.hInstance = argv;
wc.hbrBackground = GetSysColorBrush(COLOR_3DFACE);
wc.lpszMenuName = NULL;
wc.lpfnWndProc = WndProc;
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
RegisterClassW(&wc);
hwnd = CreateWindowW(wc.lpszClassName, L"Window",
WS_OVERLAPPEDWINDOW | WS_VISIBLE,
100, 100, 350, 250, NULL, NULL, hInstance, NULL);
ShowWindow(hwnd, nCmdShow);
UpdateWindow(hwnd);
while (GetMessage(&msg, NULL, 0, 0)) {
DispatchMessage(&msg);
}
return (int) msg.wParam;
}
LRESULT CALLBACK WndProc(HWND hwnd, UINT msg,
WPARAM wParam, LPARAM lParam) {
switch(msg) {
case WM_DESTROY:
PostQuitMessage(0);
break;
}
return DefWindowProcW(hwnd, msg, wParam, lParam);
}
Is there a better way?

Answer 1

You can get the .exe HMODULE/HINSTANCE with GetModuleHandle(0).
The real Windows entrypoint has no parameters, the C run-time calls GetModuleHandle for you when using WinMain.