前端渲染base64图片与上传图片转为base64格式给后台

后台返回的图片信息为base64格式，前端进行渲染

<el-button  @click="scBtnImageClick">生成</el-button>
<img :src="scBtnImageUrl" class="avatar-uploader-icon">

请求接口成功进行渲染

this.scBtnImageUrl = 'data:image/png;base64,'+res.data.img

上传图片转为base64格式给后台（vue+elementUI）

<el-upload
  :auto-upload="false"
  :show-file-list="false"
  :on-change="onChangeUpload"
  accept="image/jpeg,image/png"
  class="avatar-uploader"
  action="https://yy.xx.com">
>
  <el-button>上传</el-button>
</el-upload>
<img v-if="imageUrlUpload" :src="imageUrlUpload" class="avatar-uploader-icon">

/** base64处理 */
getBase64 (file) {
  return new Promise(function (resolve, reject) {
    let reader = new FileReader()
    let imgResult = ''
    reader.readAsDataURL(file)
    reader.onload = function () {
      imgResult = reader.result
    }
    reader.onerror = function (error) {
      reject(error);
    }
    reader.onloadend = function () {
      resolve(imgResult);
    }
  })
},
/** 上传操作 */
onChangeUpload (file) {
  this.getBase64(file.raw).then(res => {
    this.imageUrlUpload = res
  })
},