ios手机拍照旋转问题

fileUtil.js

import EXIF from 'exif-js'export default {  getOrientation: (file) => {    return new Promise((resolve) => {      EXIF.getData(file, function () {        const orient = EXIF.getTag(this, 'Orientation')        resolve(orient)      })    })  },  dataURLtoFile: (dataurl, filename) => {    const arr = dataurl.split(',')    const mime = arr[0].match(/:(.*?);/)[1]    const bstr = atob(arr[1])    let n = bstr.length    let u8arr = new Uint8Array(n);    while (n--) {      u8arr[n] = bstr.charCodeAt(n);    }    return new File([u8arr], filename, {type: mime});  },  rotateImage: (image, width, height) => {    let canvas = document.createElement('canvas')    let ctx = canvas.getContext('2d')    ctx.save()    canvas.width = height    canvas.height = width    ctx.rotate(90 * Math.PI / 180)    ctx.drawImage(image, 0, -height)    ctx.restore()    return canvas.toDataURL("image/jpeg")  },}

图片上传前对文件解析

beforeUpLoad(file) {
      return new Promise(resolve => {
        fileUtil.getOrientation(file).then(orient => {
          if (orient && orient === 6) {
            let reader = new FileReader();
            let img = new Image();
            reader.onload = e => {
              img.src = e.target.result;
              img.onload = function() {
                const data = fileUtil.rotateImage(img, img.width, img.height);
                const newFile = fileUtil.dataURLtoFile(data, file.name);
                resolve(newFile);
              };
            };
            reader.readAsDataURL(file);
          } else {
            resolve(file);
          }
        });
      });
    },