Error creating a window in windows "undefined reference to 'WinMain@16'"

Question

#ifndef UNICODE
#define UNICODE
#endif

#include <windows.h>

LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam);

int WINAPI wWinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PWSTR pCmdLine, int     nCmdShow)
{

const wchar_t CLASS_NAME[]  = L"Sample Window Class";

WNDCLASS wc = { };

wc.lpfnWndProc   = WindowProc;
wc.hInstance     = hInstance;
wc.lpszClassName = CLASS_NAME;

RegisterClass(&wc);



HWND hwnd = CreateWindowEx(
    0,
    CLASS_NAME,
    L"Learn to Program Windows",
    WS_OVERLAPPEDWINDOW,


    CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,

    NULL,
    NULL,
    hInstance,
    NULL
    );

if (hwnd == NULL)
{
    return 0;
}

ShowWindow(hwnd, nCmdShow);



MSG msg = { };
while (GetMessage(&msg, NULL, 0, 0))
{
    TranslateMessage(&msg);
    DispatchMessage(&msg);
}

return 0;
}
LRESULT CALLBACK WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
{
    switch (uMsg)
    {
    case WM_DESTROY:
    PostQuitMessage(0);
    return 0;

case WM_PAINT:
    {
        PAINTSTRUCT ps;
        HDC hdc = BeginPaint(hwnd, &ps);

        FillRect(hdc, &ps.rcPaint, (HBRUSH) (COLOR_WINDOW+1));

        EndPaint(hwnd, &ps);
    }
    return 0;

}
return DefWindowProc(hwnd, uMsg, wParam, lParam);
}

This is the code, which is also the standard example you can find in the microsoft website that teach people how to program windows. http://msdn.microsoft.com/en-us/library/windows/desktop/ff381409(v=vs.85).aspx

The problem I receive is the following whenever I try to compile this code in codeblocks.

undefined reference to 'WinMain@16'

What is that and what can I do to compile and run this piece of code?

Answer 1

It seems strange to me that WinMain is called wWinMain: evidently you need a function called WinMain.

Oh, wait, you are using codeblocks? Probably wWinMain is specific of visual studio. Codeblocks wants the standard WinMain.