js+canvas绘制五角星的方法
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。
相关推荐
jinxiutong 2020-05-10
MIKUScallion 2020-02-22
songfens 2020-01-10
大地飞鸿 2020-11-12
星星有所不知 2020-10-12
jinxiutong 2020-07-26
MIKUScallion 2020-07-05
songfens 2020-07-05
songfens 2020-06-11
songfens 2020-06-08
northwindx 2020-05-31
northwindx 2020-05-31
northwindx 2020-05-27
northwindx 2020-05-25
MIKUScallion 2020-05-25
xdyangxiaoromg 2020-05-10
大地飞鸿 2020-05-06