C++代码雨

闲逛的时候发现了一个很好玩的程序

摘自：https://blog.csdn.net/u012837895/article/details/20849967#comments

效果如下

#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 = '\0';

        cc->current->next = cc->current + 1; //cc->current+1一个显示列的后个元素 

        cc->point = cc->current++; //cc->point = cc->current; cc->current++; 

    }

    cc->current->prev = cc->point; //最后一个节点 

    cc->current->ch = '\0';

    cc->current->next = cc->head;

    cc->head->prev = cc->current; //头节点的前一个为此链的最后一个元素 

    cc->current = cc->point = cc->head; //free掉申请的内存要用current当参数 

    cc->head->ch = randomChar(); // 对链表头的 元素填充 

    return 0;

}

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)

{

    HDC          hdc;

    //ctn 用来确定一个显示链是否 向下前进,如果等待次数超过必须等待的次数,ctn就代表要向下前进 

    int i, j, temp, ctn; //j为一个显示链中除链表头外的在屏幕上显示的y坐标,temp绿色过度到黑色之用 

    static  HDC hdcMem;

    HFONT    hFont;

    static  HBITMAP hBitmap;

    static  int cxScreen, cyScreen; //屏幕的宽度 高度. 

    static  int iFontWidth = 10, iFontHeight = 15, iColumnCount; //字体的宽度 高度, 列数 

    static  CharColumn *ccChain;

    switch (message)

    {

    case WM_CREATE:

        cxScreen = GetSystemMetrics(SM_CXSCREEN); //屏幕宽度 

        cyScreen = GetSystemMetrics(SM_CYSCREEN);

        SetTimer(hwnd, ID_TIMER, 10, NULL);

        hdc = GetDC(hwnd);

        hdcMem = CreateCompatibleDC(hdc);

        hBitmap = CreateCompatibleBitmap(hdc, cxScreen, cyScreen);

        SelectObject(hdcMem, hBitmap);

        ReleaseDC(hwnd, hdc);

        //创建字体 

        hFont = CreateFont(iFontHeight, iFontWidth - 5, 0, 0, FW_BOLD, 0, 0, 0,

            DEFAULT_CHARSET, OUT_DEFAULT_PRECIS, CLIP_DEFAULT_PRECIS,

            DRAFT_QUALITY, FIXED_PITCH | FF_SWISS, TEXT("Fixedsys"));

        SelectObject(hdcMem, hFont);

        DeleteObject(hFont);

        SetBkMode(hdcMem, TRANSPARENT); //设置背景模式为 透明 

        iColumnCount = cxScreen / (iFontWidth * 3 / 2); //屏幕所显示字母雨的列数 

        ccChain = (pCharColumn)calloc(iColumnCount, sizeof(CharColumn));

        for (i = 0; i < iColumnCount; i++)

        {

            init(ccChain + i, cyScreen, (iFontWidth * 3 / 2)*i);

        }

        return 0;

    case WM_TIMER:

        hdc = GetDC(hwnd);

        PatBlt(hdcMem, 0, 0, cxScreen, cyScreen, BLACKNESS); //将内存设备映像刷成黑色 

        for (i = 0; i < iColumnCount; i++)

        {

            ctn = (ccChain + i)->iStopTimes++ > (ccChain + i)->iMustStopTimes;

            // 

            (ccChain + i)->point = (ccChain + i)->head; //point用于遍历整个显示列 

            //第一个字符显示为 白色 

            SetTextColor(hdcMem, RGB(255, 255, 255));

            TextOut(hdcMem, (ccChain + i)->x, (ccChain + i)->y, &((ccChain + i)->point->ch), 1);

            j = (ccChain + i)->y;

            (ccChain + i)->point = (ccChain + i)->point->next;

            //遍历整个显示列,将这个显示列里的字符从下往上显示 

            temp = 0; //temp绿色过度到黑色之用 

            while ((ccChain + i)->point != (ccChain + i)->head && (ccChain + i)->point->ch)

            {

                SetTextColor(hdcMem, RGB(0, 255 - (255 * (temp++) / (ccChain + i)->iStrLen), 0));

                TextOut(hdcMem, (ccChain + i)->x, j -= iFontHeight, &((ccChain + i)->point->ch), 1);

                (ccChain + i)->point = (ccChain + i)->point->next;

            }

            if (ctn)

                (ccChain + i)->iStopTimes = 0;

            else continue;

            (ccChain + i)->y += iFontHeight; //下次开始显示的y坐标 为当前的y坐标加上 一个字符的高度 

            //如果开始显示的y坐标减去 整个显示列的长度超过了屏幕的高度 

            if ((ccChain + i)->y - (ccChain + i)->iStrLen*iFontHeight > cyScreen)

            {

                free((ccChain + i)->current);

                init(ccChain + i, cyScreen, (iFontWidth * 3 / 2)*i);

            }

            //链表的头 为此链表的前个元素,因为下次开始显示的时候 就相当与在整个显示列的开头添加个元素,然后在开始往上显示 

            (ccChain + i)->head = (ccChain + i)->head->prev;

            (ccChain + i)->head->ch = randomChar();

        }

        BitBlt(hdc, 0, 0, cxScreen, cyScreen, hdcMem, 0, 0, SRCCOPY);

        ReleaseDC(hwnd, hdc);

        return 0;

    case WM_RBUTTONDOWN:

        KillTimer(hwnd, ID_TIMER);

        return 0;

    case WM_RBUTTONUP:

        SetTimer(hwnd, ID_TIMER, 10, NULL);

        return 0;

        //处理善后工作 

    case WM_KEYDOWN:

    case WM_LBUTTONDOWN:

    case WM_DESTROY:

        KillTimer(hwnd, ID_TIMER);

        DeleteObject(hBitmap);

        DeleteDC(hdcMem);

        for (i = 0; i < iColumnCount; i++)

        {

            free((ccChain + i)->current);

        }

        free(ccChain);

        PostQuitMessage(0);

        return 0;

    }

    return DefWindowProc(hwnd, message, wParam, lParam);

}