07绘制奥运五环

作者: 夜幕小草 | 来源:发表于2016-12-07 23:15 被阅读35次

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>绘制奥运五环</title>
</head>
<body style="padding: 100px;">
  <canvas id="canvas" width="900" height="600" style="border:1px solid #000"></canvas>

<script>
     // 1. 获取标签
    var canvas = document.getElementById("canvas");
    var ctx = canvas.getContext("2d");

    // 2. 绘制奥运五环
    var colorArr = ["red", "blue", "yellow", "purple", "black"];
    for(var i=0; i<colorArr.length; i++){
        ctx.beginPath();
        ctx.arc((i+1) * 100, 150, 80, 0, 2 * Math.PI);
        ctx.strokeStyle = colorArr[i]; // 设置颜色
        ctx.lineWidth = 6;
        ctx.stroke();
    }

     for(var i=0; i<colorArr.length; i++){
         ctx.beginPath();
         if(i < 3){
             ctx.arc((i+1) * 100, 350, 80, 0, 2 * Math.PI);
         }else {
             ctx.arc((i-2) * 100 + 50, 430, 80, 0, 2 * Math.PI);
         }
         ctx.strokeStyle = colorArr[i]; // 设置颜色
         ctx.lineWidth = 6;
         ctx.stroke();
     }
</script>
</body>
</html>