代码（html）：
<!DOCTYPE html>
<html>
<head>
<title>黑客帝国效果</title>
</head>
<body>
<canvas id="canvas"></canvas>
<style type="text/css">
body{margin: 0; padding: 0; overflow: hidden;}
</style>
<script type="text/javascript">
var canvas = document.getElementById('canvas');
var ctx = canvas.getContext('2d');
canvas.height = window.innerHeight;
canvas.width = window.innerWidth;
var texts = '0123456789'.split('');
var fontSize = 16;
var columns = canvas.width/fontSize;
// 用于计算输出文字时坐标，所以长度即为列数
var drops = [];
//初始值
for(var x = 0; x < columns; x++){
drops[x] = 1;
}
function draw(){
//让背景逐渐由透明到不透明
ctx.fillStyle = 'rgba(0, 0, 0, 0.05)';
ctx.fillRect(0, 0, canvas.width, canvas.height);
//文字颜色
ctx.fillStyle = '#0F0';
ctx.font = fontSize + 'px arial';
//逐行输出文字
for(var i = 0; i < drops.length; i++){
var text = texts[Math.floor(Math.random()*texts.length)];
ctx.fillText(text, i*fontSize, drops[i]*fontSize);
if(drops[i]*fontSize > canvas.height || Math.random() > 0.95){
drops[i] = 0;
}
drops[i]++;
}
}
setInterval(draw, 33);
</script>
</body>
效果图：
c++实现方式：
代码：
#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);
}