效果图
html结构
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<title>canvas2</title>
<link rel="stylesheet" href="">
</head>
<body>
<canvas id="canvas" style ="border:1px solid #aaa;diplay:block;margin:50px auto;">
当前浏览器不支持canvas,请更换浏览器后再试
</canvas>
</body>
</html>
js脚本
<script>
window.onload = function(){
var canvas = document.getElementById('canvas');
canvas.width = 800;
canvas.height = 800;
var context = canvas.getContext('2d');
context.beginPath();
context.moveTo(100,100);
context.lineTo(700,700);
context.lineTo(100,700);
context.lineTo(100,100);
context.closePath();
context.lineWidth = 10;
context.strokeStyle = "#058";
context.stroke();
}
</script>