前端通过本地图片路径 转成file格式文件

const imageUrlToBase64 = (imageUrl) => {
    let image = new Image()
    image.setAttribute('crossOrigin', 'anonymous')
    image.onload = () => {
        var canvas = document.createElement("canvas")
        canvas.width = image.width
        canvas.height = image.height
        var context = canvas.getContext('2d')
        context.drawImage(image, 0, 0, image.width, image.height)
        var quality = 0.8
        var dataURL = canvas.toDataURL("image/jpeg", quality)
        base64toFile(dataURL)
    }
    image.src = imageUrl
}

const base64toFile = (dataurl, filename = 'file') => {
    let arr = dataurl.split(',')
    let mime = arr[0].match(/:(.*?);/)[1]
    let suffix = mime.split('/')[1]
    let bstr = atob(arr[1])
    let n = bstr.length
    let u8arr = new Uint8Array(n)

    while (n--) {
        u8arr[n] = bstr.charCodeAt(n)
    }

    let file = new File([u8arr], `${filename}.${suffix}`, {
        type: mime
    })
    console.log(file)
}

const imageUrl = new URL(`@/assets/images/info-bgc.png`, import.meta.url)
onMounted(() => {
    imageUrlToBase64(imageUrl)
})