canvas实现一个圆 

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>canvas</title>
</head>
<body>
    <canvas id="canvas" width="600" height="600"></canvas>

    <script>
        let canvas = document.querySelector("#canvas");

        let ctx = canvas.getContext("2d");

        // true 表示是逆时针
        ctx.arc(200,200,100,0, Math.PI,true) //x: number, y: number, radius: number, startAngle: number, endAngle: number, counterclockwise?: boolean
        ctx.fillStyle="red"
        ctx.fill()
      
        ctx.lineWidth =3
        ctx.stroke()
    </script>
    
</body>
</html>

　　

 

posted @ 2021-12-30 21:11  前端那点事  阅读(66)  评论(0)    收藏  举报