屏保源码

//数字流星雨   作者：Wicrecend
#include "stdafx.h"
#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) ; 
}