本文实例讲述了js+canvas绘制五角星的方法。分享给大家供大家参考,具体如下:
运行效果截图如下:

具体代码如下:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><title>canvas绘制五角星 </title><script type="text/javascript" >window.onload = function () {var canvas = document.getElementById("canvas");if (canvas) {var context = canvas.getContext("2d");drawStar(context, 50, 100, 100);} else {document.writeln("浏览器不支持canvas组件");}}function drawStar(context, r, x, y) {context.lineWidth = 5;context.beginPath();var dit = Math.PI * 4 / 5;var sin = Math.sin(0) * r + y;var cos = Math.cos(0) * r + x;console.log(0+":"+0);context.moveTo(cos, sin);for (var i = 0; i < 5; i++) {var tempDit = dit * i;sin = Math.sin(tempDit) * r + y;cos = Math.cos(tempDit) * r + x;context.lineTo(cos, sin);console.log(sin+":"+sin+":"+tempDit);}context.closePath();context.strokeStyle = "red";context.fillStyle = "#DDDDDD";context.fill();}</script></head><body><canvas id="canvas" ></canvas></body></html>更多关于JavaScript相关内容感兴趣的读者可查看本站专题:《JavaScript动画特效与技巧汇总》《JavaScript运动效果与技巧汇总》及《JavaScript数据结构与算法技巧总结》
希望本文所述对大家JavaScript程序设计有所帮助。