《windows程序设计》学习_2.1：初识消息

#include <windows.h>

//#define WM_MYMSG (WM_USER +100)

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

int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance,
                   PSTR szCmdLine, int iCmdShow)
{
    static TCHAR szAppName[] = TEXT ("HelloWin");
    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,
        TEXT("The Hello Program"),
        WS_OVERLAPPEDWINDOW,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        NULL,
        NULL,
        hInstance,
        NULL);
    
    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)
{
    HDC         hdc;
    PAINTSTRUCT ps;
    RECT        rect;
    
    switch(message)
    {
    case WM_CREATE:
//        PlaySound (TEXT ("123.wav"), NULL , SND_FILENAME |SND_ASYNC);
        return 0;
        
    case WM_PAINT:
        hdc = BeginPaint(hwnd , &ps);
        
        GetClientRect(hwnd, &rect);
        
        DrawText(hdc , TEXT("Hello Windows 98!") , -1 ,&rect , 
            DT_SINGLELINE | DT_CENTER | DT_VCENTER);
        
        EndPaint(hwnd,&ps);

//        PlaySound (TEXT ("123.wav"), NULL , SND_FILENAME |SND_ASYNC);
        return 0;
/*
    case WM_MYMSG:
        PlaySound (TEXT ("123.wav"), NULL , SND_FILENAME |SND_ASYNC);
        return 0;                                                          //自定义消息
*/
    case WM_LBUTTONDOWN:
//        PlaySound (TEXT ("123.wav"), NULL , SND_FILENAME |SND_ASYNC);
//        InvalidateRect(hwnd, NULL , FALSE);
//        SendMessage(hwnd , WM_MYMSG , wParam , lParam);
        return 0;
        
    case WM_DESTROY:
//        PlaySound (TEXT ("123.wav"), NULL , SND_FILENAME |SND_ASYNC);
        PostQuitMessage(0);
        return 0;
    }
    return DefWindowProc(hwnd,message,wParam,lParam);
}