环形进度条带数字显示(canvas)

时间：2025-04-03 12:06:25
<!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>

    <meta name="viewport" content="initial-scale=1, width=device-width, maximum-scale=1, user-scalable=no">

    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

    <title></title>

</head>

<body>

<style>

    #canvas{display:block;margin:100px auto; background:#fff;}

</style>

<canvas id="canvas" width="300" height="300"></canvas>

    <script type="text/javascript">

        window.onload = function(){

            var canvas = document.getElementById("canvas");

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

            var W = canvas.width;

            var H = canvas.height;

            var deg=0,new_deg=0,dif=0;

            var loop,re_loop;

            var text,text_w;

            function init(){

                ctx.clearRect(0,0,W,H);

                ctx.beginPath();

                ctx.strokeStyle="#ebebeb";

                ctx.lineWidth=5;

                ctx.arc(W/2,H/2,70,0,Math.PI*2,false);

                ctx.stroke();

                var r = deg*Math.PI/180;

                ctx.beginPath();

                ctx.strokeStyle = "#f31437";

                ctx.lineWidth=5;

                ctx.arc(W/2,H/2,70,0-90*Math.PI/180,r-90*Math.PI/180,false);

                ctx.stroke();

                ctx.fillStyle="#f00";

                ctx.font="50px abc";

                text = Math.floor(deg/360*100)+"%";

                text_w = ctx.measureText(text).width;

                ctx.fillText(text,W/2 - text_w/2,H/2+15);

            }

            function draw(){

                new_deg = 250;//设置角度

                loop = setInterval(to,1000/dif);

            }

            function to(){

                if(deg == new_deg){

                    clearInterval(loop);

                }

                if(deg<new_deg){

                    deg++;

                }else{

                    deg--;

                }

                init();

            }

            draw();

            re_loop = setInterval(draw,2000);

        }

    </script>

</body>

</html>

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