<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title></title>
</head>
<body>
<!-- canvas的width/height默认都是300 -->
<canvas id="fillRect" width="100" height="100"></canvas>
<canvas id="strokeRect" width="100" height="100"></canvas>
<canvas id="arc" width=" 400" height="400"></canvas>
<script type="text/javascript">
function canvasFillRect(id) {//绘制矩形 实心
var canvas = document.getElementById(id);
var context = canvas.getContext("2d");
context.fillStyle = "pink";
context.fillRect(0, 0, 100, 100);
}
canvasFillRect("fillRect");
function canvasStrokeRect(id) {//绘制矩形 空心
var canvas = document.getElementById(id);
var context = canvas.getContext("2d");
context.strokeStyle = "red";
context.strokeRect(0, 0, 100, 100);
}
canvasStrokeRect("strokeRect");
function canvasArc(id) {//绘制圆心 实心 空心
var canvas = document.getElementById(id);
var context = canvas.getContext("2d");
//实心
context.fillStyle = "green";
context.beginPath();
context.arc(100, 100, 50, 0, Math.PI * 2, true);
context.closePath();
context.fill();
//空心
context.beginPath();
context.arc(210, 100, 50, 0, Math.PI * 2, true);
context.closePath();
context.strokeStyle = "yellow";
context.stroke();
}
canvasArc("arc");
</script>
</body>
</html>