WinAppi - tworzenie okna.

#include <Windows.h>


HWND ghMainWnd = 0;

bool InitWindowsApp( HINSTANCE instanceHandle, int show );

int Run();

LRESULT CALLBACK
WndProc( HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam );

int WINAPI
WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR pCmdLine, int nShowCmd )
{
    if( !InitWindowsApp( hInstance, nShowCmd ) )
         return 0;
   
    return Run();
}

bool InitWindowsApp( HINSTANCE instanceHandle, int show )
{
    WNDCLASS wc;
   
    wc.style = CS_HREDRAW | CS_VREDRAW;
    wc.lpfnWndProc = WndProc;
    wc.cbClsExtra = 0;
    wc.cbWndExtra = 0;
    wc.hInstance = instanceHandle;
    wc.hIcon = LoadIcon( 0, IDI_APPLICATION );
    wc.hCursor = LoadCursor( 0, IDC_ARROW );
    wc.hbrBackground =( HBRUSH ) GetStockObject( WHITE_BRUSH );
    wc.lpszMenuName = 0;
    wc.lpszClassName = L"BassicWndClass";
   
    if( !RegisterClass( & wc ) )
    {
        MessageBox( 0, L"RegisterClass FAILED", 0, 0 );
        return false;
    }
   
    ghMainWnd = CreateWindow(
    L"BasicWndClass",
    L"Win32Basic",
    WS_OVERLAPPEDWINDOW,
    CW_USEDEFAULT,
    CW_USEDEFAULT,
    CW_USEDEFAULT,
    CW_USEDEFAULT,
    0,
    0,
    instanceHandle,
    0 );
   
    if( ghMainWnd == 0 )
    {
        MessageBox( 0, L"CreateWindow FAILED", 0, 0 );
        return false;
    }
   
    ShowWindow( ghMainWnd, show );
    UpdateWindow( ghMainWnd );
   
    return true;
}

int Run()
{
    MSG msg = { 0 };
   
    BOOL bRet = 1;
    while(( bRet = GetMessage( & msg, 0, 0, 0 ) ) != 0 )
    {
        if( bRet == - 1 )
        {
            MessageBox( 0, L"GetMessage FAILED", L"Error", MB_OK );
            break;
        }
        else
        {
            TranslateMessage( & msg );
            DispatchMessage( & msg );
           
        }
    }
    return( int ) msg.wParam;
}
LRESULT CALLBACK
WndProc( HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam )
{
    switch( msg )
    {
    case WM_LBUTTONDOWN:
        MessageBox( 0, L"Hello, World", L"Hello", MB_OK );
        return 0;
    case WM_KEYDOWN:
        if( wParam == VK_ESCAPE )
             DestroyWindow( ghMainWnd );
       
        return 0;
    case WM_DESTROY:
        PostQuitMessage( 0 );
        return 0;
    }
    return DefWindowProc( hWnd, msg, wParam, lParam );
}