Vue将base64图片转为File文件类型

base64ToFile(urlData, fileName) {
    let arr = urlData.split(',');
    let mime = arr[0].match(/:(.*?);/)[1];
    let bytes = atob(arr[1]); // 解码base64
    let n = bytes.length
    let ia = new Uint8Array(n);
    while (n--) {
        ia[n] = bytes.charCodeAt(n);
    }
    return new File([ia], fileName, { type: mime });
},