如何在 JavaScript 中绘制圆形?

javascriptweb developmentobject oriented programming更新于 2025/9/3 13:32:17

以下是在 JavaScript 中绘制圆形的代码 −

示例

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Document</title>
<style>
   body {
      font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
   }
   .circleCanvas {
      border: 3px solid #110101;
   }
</style>
</head>
<body>
<h1>Draw a circle in JavaScript</h1>
<canvas class="circleCanvas" width="400" height="200"></canvas><br />
<button class="btn">点击此处</button>
<h3>Click on the above button to create a circle in the above canvas element</h3>
<script>
   let canvasEle = document.querySelector(".circleCanvas");
   let BtnEle = document.querySelector(".Btn");
   BtnEle.addEventListener("click", () => {
      var circle = canvasEle.getContext("2d");
      circle.beginPath();
      circle.arc(180, 100, 90, 0, 2 * Math.PI);
      circle.stroke();
   });
</script>
</body>
</html>