使用File, FormData将图片的blob数据进行图片旋转然后上传操作

if (this.currentImg && this.currentImg.path) {
  this.rotateNum++;
  let degree = 0;
  let rotateInput = this.rotateNum * 90;
  degree += parseInt(rotateInput);
  degree %= 360;
  let img = new Image();
  img.setAttribute("crossOrigin",'Anonymous');
  img.src = this.currentImg.path;
  img.onload = () => {
    let $w = img.width, $h = img.height, $c = document.getElementById("uploadImageCanvas");
    let ctx = $c.getContext("2d");
    if (degree === 90) {
      $c.width = $h;
      $c.height = $w;
      ctx.clearRect(0, 0, $h, $w);
      ctx.rotate(degree / 180 * Math.PI);
      ctx.translate(0, -$h);
      ctx.drawImage(img, 0, 0);
    } else if (degree === 270) {
      $c.width = $h;
      $c.height = $w;
      ctx.clearRect(0, 0, $h, $w);
      ctx.rotate(degree / 180 * Math.PI);
      ctx.translate(-$w, 0);
      ctx.drawImage(img, 0, 0);
    } else {
      $c.width = $w;
      $c.height = $h;
      ctx.clearRect(0, 0, $w, $h);
      ctx.translate($w / 2, $h / 2);
      ctx.rotate(degree / 180 * Math.PI);
      ctx.translate(-$w / 2, -$h / 2);
      ctx.drawImage(img, $w / 2 - $w / 2, $h / 2 - $h / 2);
    }
    $c.toBlob((blob) => {
      let fd = new FormData();
      let fileBlob = new File([blob], new Date().getTime() + '.png')
      fd.append("file", fileBlob);
      CommonPOSThandUpload(fd).then((response) => {
        if (response && response.data) {
          let oRes = response.data;
          if (oRes) {
            this.setImgUid(oRes);
          }
        }
      })
    });
  }
} else {
  this.rotateNum = 0;
}