URL.createObjectURL 图像长按保存时其上浮动的元素也被截取了
```
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script src="https://unpkg.com/@zumer/snapdom@1.9.14/dist/snapdom.min.js" referrerpolicy="no-referrer"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.7.1/jquery.min.js" referrerpolicy="no-referrer"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/qrcodejs/1.0.0/qrcode.min.js" referrerpolicy="no-referrer"></script>
<style>
* {
margin: 0;
padding: 0;
box-sizing: border-box;
}
.box {
margin: 0 auto;
width: 750px;
position: relative;
}
.poster {
font-size: 0;
}
.posterImg {
width: 750px;
height: 1334px;
}
.qrBox {
position: absolute;
right: 70px;
top: 1122px;
width: 120px;
height: 120px;
}
.qrBox img {
width: 100%;
}
.shareImg {
position: fixed;
width: 750px;
height: 1334px;
font-size: 0;
}
.shareImg img {
width: 375px;
}
button {
position: fixed;
left: calc(50% - 100px);
bottom: 50px;
width: 200px;
height: 40px;
display: flex;
justify-content: center;
align-items: center;
border-radius: 10px;
background-color: #2caff7;
color: #fff;
border: none;
cursor: pointer;
}
.preview {
position: relative;
}
.tip {
position: fixed;
z-index: 1;
}
</style>
</head>
<body>
<div class="box">
<div class="poster">
<img src="p1.jpg" class="posterImg"/>
<div class="qrBox"></div>
</div>
</div>
<div class="preview">
<div class="tip">文字</div>
<div class="shareImg">
<!-- <img :src="shareData" /> -->
</div>
</div>
<button id="btn">snap</button>
<script>
function xx() {
snapdom.toCanvas(document.querySelector('.poster'), {
fast:false,
}).then(blob => {
// mock vue update
let data = blob.toDataURL('png')
let img = `<img src="${data}" />`
$('.shareImg').html(img)
$('.box').hide()
})
}
$(function () {
new QRCode(document.querySelector('.qrBox'), {
text: "123",
width: 128,
height: 128,
})
$('#btn').click(function () {
snapdom.toBlob(document.querySelector('.poster'), {
fast:false,
type: 'png'
}).then(blob => {
// mock vue update
let data = URL.createObjectURL(blob)
let img = `<img src="${data}" />`
$('.shareImg').html(img)
$('.box').hide()
})
})
})
</script>
</body>
</html>
```
