<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
</head>
<body>
<canvas width="1000" height="600" id="cv"></canvas>
</body>
</html>
<script>
let cv = document.getElementById("cv");
var ctx = cv.getContext('2d');
let img = new Image();
img.src = "./arrow.png"; // 图片自己找张吧
img.onload = function () {
var opacity = 1;
setInterval(() => {
opacity-=.01
ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height)
ctx.globalAlpha = opacity;
ctx.drawImage(img, 0, 0, 250, 167);
ctx.globalAlpha = 1; // 在渲染其他正常图片时要恢复全局透明度
ctx.drawImage(img, 100, 200, 250, 167);
if(opacity <= 0){
opacity = 1;
}
}, 10);
}
</script>
<style>
* {
padding: 0;
margin: 0;
}
canvas {
/* border: 1px solid; */
}
</style>
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