How to fix "undefined reference to 'WinMain@16'" problem?

[AceDawg45]

So, I am messing around on the Windows Dev Center (http://msdn.microsoft.com/en-us/library/windows(dont have to click that)) and I wanted to see how they say to create a window, and I tried it and the debugger says: undefined reference to WinMan@16.

What does that mean?!?!? Here is my code:

#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, PWSTR pCmdLine, int nCmdShow)
{
    // Register the window class.
    const wchar_t CLASS_NAME[]  = L"Sample Window Class";

    WNDCLASS wc = { };

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

    RegisterClass(&wc);

    // Create the window.

    HWND hwnd = CreateWindowEx(
        0,                              // Optional window styles.
        CLASS_NAME,                     // Window class
        L"Learn to Program Windows",    // Window text
        WS_OVERLAPPEDWINDOW,            // Window style

        // Size and position
        CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,

        NULL,       // Parent window
        NULL,       // Menu
        hInstance,  // Instance handle
        NULL        // Additional application data
        );

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

    ShowWindow(hwnd, nCmdShow);

    // Run the message loop.

    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);
}

[LB]

You accidentally named your function wWinMain instead of WinMain, so your linker has no idea where to find the main entry point for your windows API application.

[AceDawg45]

Well, I just changed it and it still says it. I cant find any other places where it is wrong. Any other suggestions?

[Disch]

PWSTR is also wrong... it's supposed to be LPSTR:

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE, LPSTR pCmdLine, int nCmdShow)

[S G H]

Actually, wWinMain (and the PWSTR thing too) work for unicode.

[Disch]

But then would he have to configure his linker to look for the wide entry point?

[AceDawg45]

Alright, thanks everybody I fixed it. WinMain and LPSTR instead of wWinMain and etc. whatever, I will try and remember that for next time

[modoran]

Are you using MinGW, don't you ? If so, you should know that MinGW runtime does not implement wWinMain or wmain entry points.

[AceDawg45]

YEaah I am. Where do I get MinGW Ru ntime? (or how...)

[Disch]

If you have MinGW, you already have the runtime.

He was just saying that the wWinMain doesn't work with MinGW... which is why you had to use WinMain instead.

[AceDawg45]

Oh. Well that makes sense. I was wondering why they have two different compilers with the same name.... (basically same)

[S G H]

MinGW Runtime = The DLLs required for applications built with MinGW
MinGW = Tools to build applications made with MinGW (huh)

Same happens for any other compiler.

<x> Runtime = Requirements for running applications build with <x>
(Usually DLLs)