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<head><meta charset="utf-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><title>canvas圓環進度</title><link rel="stylesheet" href=""><style>*{padding: 0; margin: 0; }.circle{width: 200px;height: 200px;margin: 20em auto;position: relative;}canvas{display: block;margin: 0;position: absolute;background: white;left: 0;top: 0;}#canvas_1{z-index: 1 }#canvas_2{z-index: 2; background: transparent;transform:rotate(-90deg); }</style>
</head>
<body><div class="circle"><canvas id="canvas_1" width="200" height="200"></canvas><canvas id="canvas_2" width="200" height="200"></canvas></div><script>function inte(percent) {var canvas_1 = document.querySelector('#canvas_1');var canvas_2 = document.querySelector('#canvas_2');var ctx_1 = canvas_1.getContext('2d');var ctx_2 = canvas_2.getContext('2d');ctx_1.lineWidth = 10;ctx_1.strokeStyle = "#ccc";//畫底部的灰色圓環ctx_1.beginPath();ctx_1.arc(canvas_1.width / 2, canvas_1.height / 2, canvas_1.width / 2 - ctx_1.lineWidth / 2, 0, Math.PI * 2, false);ctx_1.closePath();ctx_1.stroke();if (percent < 0 || percent > 100) {throw new Error('percent must be between 0 and 100');return}ctx_2.lineWidth = 10;ctx_2.strokeStyle = "#f90";var angle = 0;var timer;(function draw() {timer = requestAnimationFrame(draw);ctx_2.clearRect(0, 0, canvas_2.width, canvas_2.height)//百分比圓環ctx_2.beginPath();ctx_2.arc(canvas_2.width / 2, canvas_2.height / 2, canvas_2.width / 2 - ctx_2.lineWidth / 2, 0, angle * Math.PI / 180, false);angle++;var percentAge = parseInt((angle / 360) * 100)if (angle > (percent / 100 * 360)) {percentAge = percentwindow.cancelAnimationFrame(timer);};ctx_2.stroke();ctx_2.closePath();ctx_2.save();ctx_2.beginPath();ctx_2.rotate(90 * Math.PI / 180)ctx_2.font = '30px Arial';ctx_2.fillStyle = 'red';var text = percentAge + '%';ctx_2.fillText(text, 80, -90);ctx_2.closePath();ctx_2.restore();})()}window.onload = inte(60);</script>
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效果圖：試試吧~~
之間的地表距離)
