以下是源代码，不做解释
<canvas id="q"></canvas>
<script>
var s = window.screen;
var width = q.width = s.width;
var height = q.height = s.height;
var letters = Array(256).join(1).split('');
var draw = function () {
q.getContext('2d').fillStyle='rgba(0,0,0,.05)';
q.getContext('2d').fillRect(0,0,width,height);
q.getContext( 阅读全文>>
