JS将base64转换成file

dataURLtoBlob(dataurl, name) {//base64转file
      var arr = dataurl.split(','),
        mime = arr[0].match(/:(.*?);/)[1],
        bstr = atob(arr[1]),
        n = bstr.length,
        u8arr = new Uint8Array(n)
      while (n--) {
        u8arr[n] = bstr.charCodeAt(n)
      }
      return new File([u8arr], name, {
        type: mime,
      })
    },

this.dataURLtoBlob(imgDataUrl,name)//imgDataUrl是base64格式编码  name是图片名字