实现原理是使用设计稿尺寸和现屏幕的比例使用transform进行缩放
<!DOCTYPE html>
<html lang="zh">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title></title>
</head>
<body>
<style>
* {
margin: 0;
padding: 0;
}
.box {
width: 100vw;
height: 100vh;
background-image: url('./img/3.png');
background-size: 100% 100%;
background-repeat: no-repeat;
position: relative;
}
#canvas {
position: absolute;
z-index: 10;
}
.tips {
position: absolute;
z-index: 10;
color: red;
width: 100px;
height: 50px;
left: 50.7vw;
top: 21.8vw;
border: 3px solid red;
text-align: center;
line-height: 50px;
background-color: rgba(255, 255, 255, 0.3);
}
</style>
<div class="box">
<div class="tips">椅子</div>
<canvas id="canvas"></canvas>
</div>
<script>
const canvas = document.getElementById('canvas');
console.log(window.innerWidth, window.innerHeight)
const width = window.innerWidth;
const height = window.innerHeight;
canvas.width = width;
canvas.height = height;
let context = canvas.getContext("2d");
let x = width/1920;
let y = height/1080;
context.transform(x,0,0,y,0,0)
context.strokeStyle = "red";
context.lineWidth = 3;
context.moveTo(880, 450);
context.lineTo(975, 450);
context.save(); //可以临时保存，后面可以设置别的线宽和颜色
context.stroke();
context.moveTo(1900,0)
context.lineTo(1900,10);
context.stroke();
</script>
</body>
</html>