HBITMAP hBm;

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
LPSTR lpCmdLine, int nCmdShow)
{
MSG Message;
hBm = LoadBitmap(hInstance, "IDB_BITMAP1");
if (hBm == NULL)
{
return FALSE;
}
……
}

hBm总是 NULL。

hBm = LoadBitmap(hInstance, "IDB_BITMAP1");

改为 hBm = LoadBitmap(hInstance, MAKEINTRESOURCE（IDB_BITMAP1）);