<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Document</title> </head> <body> <canvas id="canvas" style="border: 1px #ddd solid;display: block;margin:0 auto"></canvas> <script> window.onload = function(){ var canvas = document.getElementById('canvas'); canvas.width = 1024; canvas.height = 768; if(canvas.getContext('2d')){ var context = canvas.getContext('2d'); context.lineWidth = 5; context.strokeStyle = "#005588"; for(var i=0;i<10;i++){ context.beginPath(); context.arc(50+i*100,50,40,0,2*Math.PI*(i+1)/10,false); context.closePath(); context.stroke() } for(var i=0;i<10;i++){ context.beginPath(); context.arc(50+i*100,200,40,0,2*Math.PI*(i+1)/10,false); // context.closePath(); context.stroke() } for(var i=0;i<10;i++){ context.beginPath(); context.arc(50+i*100,350,40,0,2*Math.PI*(i+1)/10,false); context.closePath(); context.stroke(); context.fillStyle ="#005588" context.fill(); } }else{ alert('當前遊覽器不支持Canvas,請更換遊覽器後再試!'); } } </script> </body> <script> /* 總結 context.arc( (圓心x 圓心y 半徑r) centerx,centery,radius, (起始角度,終止角度) startingAngle,endingAngle, (false 順時針繪製) anticlockwise = false ) */ </script> </html>