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脚本简介
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>HTML5 Canvas彩色小球碰撞运动特效 - 何问起</title> <base target="_blank" /> <style> #hovertreeball { border: 1px dashed #999; box-shadow: 0px 4px 40px #233; background: black; } .hovertreeinfo{text-align:center;} a{color:blue;} </style> </head> <body> <div class="hovertreeinfo" > 提示：可以点击按钮改变背景颜色<br /> <canvas id="hovertreeball" width="800" height="600"></canvas> </div> <script type="text/javascript"> var canvas = document.getElementById("ho"+"vertreeball"); var context = canvas.getContext("2d"); var maxWidth = canvas.width; var maxHeight = canvas.height; var colors = ["#33B5E5", "#0099CC", "#AA66CC", "#9933CC", "#99CC00", "#669900", "#FFBB33", "#FF8800", "#FF4444", "#CC0000"] //随机数 function random(min, max) { return Math.floor(Math.random() * (max - min) + min) } //构造函数 function Ball() { this.a = true; this.b = true; this.r = random(10, 30); this.ballColor = { color: colors[Math.floor(Math.random() * colors.length)] } this.vx = random(30, maxWidth - 30); this.vy = random(30, maxHeight - 30); this.ispeed = random(1, 10); this.ispeed2 = random(1, 10); } // 面向对象 Ball.prototype.moveBall = function () { context.beginPath(); if (this.a) { this.vx += this.ispeed; if (this.vx >= maxWidth - this.r) { this.a = false; } } else { this.vx -= this.ispeed; if (this.vx <= this.r) { this.a = true; } } if (this.b) { this.vy += this.ispeed2; if (this.vy >= maxHeight - this.r) { this.b = false; } } else { this.vy -= this.ispeed2; if (this.vy <= this.r) { this.b = true; } } context.fillStyle = this.ballColor.color; context.arc(this.vx, this.vy, this.r, 0, Math.PI * 2, false); context.fill(); } var Aball = []; for (var i = 0; i < 100; i++) { Aball[i] = new Ball(); } setInterval(function () { context.clearRect(0, 0, canvas.width, canvas.height) for (var i = 0; i < 100; i++) { Aball[i].moveBall(); } }, 30) function hovertreecolor() { if (canvas.style.backgroundColor != "white") { canvas.style.backgroundColor = "white"; } else { canvas.style.backgroundColor = "black"; } } </script> <div style="text-align:center;margin:10px 0; font:normal 14px/24px ‘MicroSoft YaHei‘;"> <button id="hovertreechange">改变背景颜色</button> <p>适用浏览器：FireFox、Chrome、Safari、Opera、傲游、搜狗、世界之窗等. 不支持IE8及以下浏览器。</p> <p>来源：<a href="http://hovertree.com/" target="_blank">何问起</a> <a href="http://hovertree.com/menu/texiao/">网页特效</a> <a href="http://hovertree.com/h/bjaf/mll8cpr3.htm">代码说明</a></p> </div> <script> document.getElementById("hover" + "treechange").addEventListener("click", hovertreecolor) </script> </body> </html>
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原文地址：http://www.cnblogs.com/roucheng/p/html5ball.html
