Пример WinAPI приложения

#include <windows.h>
 
LRESULT CALLBACK WndProc(HWND hwnd, UINT Message, WPARAM wParam, LPARAM lParam) {
    switch(Message) {
        case WM_DESTROY: {
            PostQuitMessage(0);
            break;
        }
        default:
            return DefWindowProc(hwnd, Message, wParam, lParam);
    }
    return 0;
}
 
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) {
    WNDCLASSEX wc;
    HWND hwnd;
    MSG Msg;
 
    memset(&wc,0,sizeof(wc));
    wc.cbSize        = sizeof(WNDCLASSEX);
    wc.lpfnWndProc   = WndProc;
    wc.hInstance     = hInstance;
    wc.hCursor       = LoadCursor(NULL, IDC_ARROW);
    
    wc.hbrBackground = (HBRUSH)(COLOR_WINDOW+1);
    wc.lpszClassName = "WindowClass";
    wc.hIcon         = LoadIcon(NULL, IDI_APPLICATION);
    wc.hIconSm       = LoadIcon(NULL, IDI_APPLICATION);
 
    if(!RegisterClassEx(&wc)) {
        MessageBox(NULL, "Window Registration Failed!","Error!",MB_ICONEXCLAMATION|MB_OK);
        return 0;
    }
 
    hwnd = CreateWindowEx(WS_EX_CLIENTEDGE,"WindowClass","Caption",WS_VISIBLE|WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        640,
        480,
        NULL,NULL,hInstance,NULL);
 
    if(hwnd == NULL) {
        MessageBox(NULL, "Window Creation Failed!","Error!",MB_ICONEXCLAMATION|MB_OK);
        return 0;
    }
 
    while(GetMessage(&Msg, NULL, 0, 0) > 0) {
        TranslateMessage(&Msg);
        DispatchMessage(&Msg);
    }
    return Msg.wParam;
}