C++代码雨

#include <windows.h> 

#define ID_TIMER    1 

#define STRMAXLEN  25 //一个显示列的最大长度 

#define STRMINLEN  8  //一个显示列的最小长度 

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

////////////////////////////////////////////////////////////////// 

////////////////////////////////////////////////////////////////// 

typedef struct tagCharChain //整个当作屏幕的一个显示列,这是个双向列表 
{

    struct tagCharChain *prev; //链表的前个元素 

    TCHAR  ch;                  //一个显示列中的一个字符 

    struct tagCharChain *next; //链表的后个元素 

}CharChain, *pCharChain;


typedef struct tagCharColumn

{

    CharChain *head, *current, *point;

    int x, y, iStrLen; //显示列的开始显示的x,y坐标,iStrLen是这个列的长度 

    int iStopTimes, iMustStopTimes; //已经停滞的次数和必须停滞的次数,必须停滞的次数是随机的 

}CharColumn, *pCharColumn;




int main(HINSTANCE hInstance, HINSTANCE hPrevInstance,
    PSTR szCmdLine, int iCmdShow)

{

    static TCHAR szAppName[] = TEXT("matrix");

    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(BLACK_BRUSH);

    wndclass.lpszMenuName = NULL;

    wndclass.lpszClassName = szAppName;




    if (!RegisterClass(&wndclass))

    {

        MessageBox(NULL, TEXT("此程序必须运行在NT下!"), szAppName, MB_ICONERROR);

        return 0;

    }




    hwnd = CreateWindow(szAppName, NULL,

        WS_DLGFRAME | WS_THICKFRAME | WS_POPUP,

        0, 0,

        GetSystemMetrics(SM_CXSCREEN), GetSystemMetrics(SM_CYSCREEN),

        NULL, NULL, hInstance,

        NULL);




    ShowWindow(hwnd, SW_SHOWMAXIMIZED); //最大化显示 

    UpdateWindow(hwnd);

    ShowCursor(FALSE); //隐藏鼠标光标 




    srand((int)GetCurrentTime()); //初始化随机数发生器 

    while (GetMessage(&msg, NULL, 0, 0))

    {

        TranslateMessage(&msg);

        DispatchMessage(&msg);

    }

    ShowCursor(TRUE); //显示鼠标光标 

    return msg.wParam;

}




TCHAR randomChar() //随机字符产生函数 

{

    return (TCHAR)(rand() % (126 - 33) + 33); //33到126之间 

}




int init(CharColumn *cc, int cyScreen, int x) //初始化 

{

    int j;

    cc->iStrLen = rand() % (STRMAXLEN - STRMINLEN) + STRMINLEN; //显示列的长度 

    cc->x = x + 3;        //显示列的开始显示的x坐标 

    cc->y = rand() % 3 ? rand() % cyScreen : 0; //显示列的开始显示的y坐标 

    cc->iMustStopTimes = rand() % 6;

    cc->iStopTimes = 0;

    cc->head = cc->current =

        (pCharChain)calloc(cc->iStrLen, sizeof(CharChain)); //生成显示列 

    for (j = 0; j < cc->iStrLen - 1; j++)

    {

        cc->current->prev = cc->point; //cc->point一个显示列的前个元素 

        cc->current->ch = '