<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<canvas id="canvas" style="border:1px solid #ccc;display:block;">
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</canvas>
<script>
window.onload = function () {
var canvas = document.getElementById('canvas');
var context = canvas.getContext('2d');
canvas.width = 1200;
canvas.height = 800;
context.lineWidth = 5;
context.strokeStyle = 'black';
for (var i = 0; i < 10; i++) {
context.beginPath();
context.arc(50 + i * 100, 60, 40, 0 , 0.2 * (i + 1) * Math.PI);
// context.arc(圆心x轴坐标,圆心y轴坐标,半径,起始点,终点,[顺时针/逆时针，true为逆时针，默认为false]);
context.closePath();
context.stroke();
};
for (var i = 0; i < 10; i++) {
context.beginPath();
context.arc(50 + i * 100, 200, 40, 0 , 0.2 * (i + 1) * Math.PI);
context.stroke();
};
for (var i = 0; i < 10; i++) {
context.beginPath();
context.arc(50 + i * 100, 400, 40, 0 , 0.2 * (i + 1) * Math.PI, true);
context.closePath();
context.stroke();
};
context.fillStyle = 'orange';
for (var i = 0; i < 10; i++) {
context.beginPath();
context.arc(50 + i * 100, 600, 40, 0 , 0.2 * (i + 1) * Math.PI, true);
context.stroke();
context.fill();
};
}
</script>
</body>
</html>
