解决uniapp uni.downloadFile(文件下载)，不识别uni.saveFile的问题``` 保存文件 `

<!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>
    <input type="file">
    <button>保存文件</button>
</body>
<script>
    const input = document.querySelector('input')
    let url = ''
    input.onchange = () => {
        url = URL.createObjectURL(input.files[0])
        console.log(url, url.file, '----url')
    }

    const btn = document.querySelector('button')
    btn.addEventListener('click', () => {
        if (!url) return false
        saveFile(url, 'test')
    })
    const saveFile = (url, fileName) => {
        const link = document.createElement('a')
        link.href = url
        link.download = `${fileName}_${Date.now()}`; // a标签添加属性
        link.style.display = 'none';
        document.body.appendChild(link)
        link.click()
        URL.revokeObjectURL(url)
        document.body.removeChild(link)

    }
</script>

</html>