#include <windows.h>#define ID_TIMER 1#define STRMAXLEN 25 //一個顯示列的最大長度#define STRMINLEN 8 //一個顯示列的最小長度LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////typedef struct tagCharChain //整個當作屏幕的一個顯示列,這是個雙向列表{  struct tagCharChain *prev; //鏈表的前個元素  TCHAR ch;     //一個顯示列中的一個字符  struct tagCharChain *next; //鏈表的后個元素}CharChain, *pCharChain;typedef struct tagCharColumn{  CharChain *head, *current, *point;  int x, y, iStrLen; //顯示列的開始顯示的x,y坐標,iStrLen是這個列的長度  int iStopTimes, iMustStopTimes; //已經停滯的次數和必須停滯的次數,必須停滯的次數是隨機的}CharColumn, *pCharColumn;int WinMain(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 ("此程序必須運行在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) ; //最大化顯示  UpdateWindow (hwnd) ;  ShowCursor(FALSE); //隱藏鼠標光標  srand ((int) GetCurrentTime ()) ; //初始化隨機數發生器  while (GetMessage (&msg, NULL, 0, 0)){   TranslateMessage (&msg) ;   DispatchMessage (&msg) ;  }  ShowCursor(TRUE); //顯示鼠標光標  return msg.wParam ;}TCHAR randomChar() //隨機字符產生函數{  return (TCHAR)(rand()%(126-33)+33); //33到126之間}int init(CharColumn *cc, int cyScreen, int x) //初始化{  int j;  cc->iStrLen = rand()%(STRMAXLEN-STRMINLEN) + STRMINLEN; //顯示列的長度  cc->x = x+3 ;  //顯示列的開始顯示的x坐標  cc->y =rand()%3?rand()%cyScreen:0; //顯示列的開始顯示的y坐標  cc->iMustStopTimes = rand()%6 ;  cc->iStopTimes = 0 ;  cc->head = cc->current =      (pCharChain)calloc(cc->iStrLen, sizeof(CharChain)); //生成顯示列  for(j=0; j<cc->iStrLen-1; j++)  {    cc->current->prev = cc->point; //cc->point一個顯示列的前個元素    cc->current->ch = '';    cc->current->next = cc->current+1; //cc->current+1一個顯示列的后個元素    cc->point   = cc->current++; //cc->point = cc->current; cc->current++;  }  cc->current->prev = cc->point; //最后一個節點  cc->current->ch = '';  cc->current->next = cc->head;cc->head->prev = cc->current; //頭節點的前一個為此鏈的最后一個元素  cc->current = cc->point = cc->head; //free掉申請的內存要用current當參數  cc->head->ch = randomChar(); // 對鏈表頭的 元素填充  return 0;}LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam){  HDC   hdc ;  //ctn 用來確定一個顯示鏈是否 向下前進,如果等待次數超過必須等待的次數,ctn就代表要向下前進  int i, j, temp, ctn; //j為一個顯示鏈中除鏈表頭外的在屏幕上顯示的y坐標,temp綠色過度到黑色之用  static HDC hdcMem;  HFONT hFont;  static HBITMAP hBitmap;  static int cxScreen, cyScreen; //屏幕的寬度 高度.  static int iFontWidth=10, iFontHeight=15, iColumnCount; //字體的寬度 高度, 列數  static CharColumn *ccChain;  switch (message)  {  case WM_CREATE:   cxScreen = GetSystemMetrics(SM_CXSCREEN) ; //屏幕寬度   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);   //創建字體   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); //設置背景模式為 透明   iColumnCount = cxScreen/(iFontWidth*3/2); //屏幕所顯示字母雨的列數   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) ; //將內存設備映像刷成黑色   for(i=0; i<iColumnCount; i++)   {    ctn = (ccChain+i)->iStopTimes++ > (ccChain+i)->iMustStopTimes;    //    (ccChain+i)->point = (ccChain+i)->head; //point用于遍歷整個顯示列    //第一個字符顯示為 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;    //遍歷整個顯示列,將這個顯示列里的字符從下往上顯示    temp = 0 ; //temp綠色過度到黑色之用    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; //下次開始顯示的y坐標 為當前的y坐標加上 一個字符的高度    //如果開始顯示的y坐標減去 整個顯示列的長度超過了屏幕的高度    if( (ccChain+i)->y-(ccChain+i)->iStrLen*iFontHeight > cyScreen)    {      free( (ccChain+i)->current ); init(ccChain+i, cyScreen, (iFontWidth*3/2)*i);    }    //鏈表的頭 為此鏈表的前個元素,因為下次開始顯示的時候 就相當與在整個顯示列的開頭添加個元素,然后在開始往上顯示    (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;  //處理善后工作  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) ;}