VC++ WIN32编程基本窗口

#include <windows.h>

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,PSTR szCmdLine, int iCmdShow)
{
    TCHAR szAppName[] = TEXT ("Simple Window ") ;
    HWND hwnd ;
    MSG msg ;

    WNDCLASS wndclass ;
    wndclass.style    = CS_HREDRAW | CS_VREDRAW ;
    wndclass.lpfnWndProc  = WndProc ;
    wndclass.cbClsExtra   = 0 ;
    wndclass.cbWndExtra   = 0 ;
    wndclass.hInstance   = hInstance ;
    wndclass.hIcon    = LoadIcon (NULL, IDI_APPLICATION) ;
    wndclass.hCursor   = LoadCursor (NULL, IDC_ARROW) ;
    wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;
    wndclass.lpszMenuName =NULL;
    wndclass.lpszClassName = szAppName ;

    if (!RegisterClass (&wndclass))
    {
        MessageBox ( NULL, TEXT ("This program requires Windows NT!"), 
                szAppName, MB_ICONERROR) ;
      return 0 ;
    }

     hwnd = CreateWindow( szAppName, // window class name
                szAppName, // window caption
                WS_OVERLAPPEDWINDOW, // window style
                CW_USEDEFAULT, // initial x position
                CW_USEDEFAULT, // initial y position
                CW_USEDEFAULT, // initial x size
                CW_USEDEFAULT, // initial y size
                NULL,   // parent window handle
                NULL,         // window menu handle
                hInstance,     // program instance handle
                NULL) ;      // creation parameters
     
     ShowWindow (hwnd, iCmdShow) ;
     UpdateWindow (hwnd) ;
    
     while (GetMessage (&msg, NULL, 0, 0))
    {
        TranslateMessage (&msg) ;
        DispatchMessage (&msg) ;
    }
     return msg.wParam ;
}

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