vueelementadmin-上传upload图片慢问题处理

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前言

vue-element-admin 自带上传图片组件，在使用的过程中发现上传速度很慢，尤其是上传一些大图需要耗时几十秒不能忍受。出现这种情况，是因为 upload 组件会将图片上传到 action="https://httpbin.org/post"，并返回转换成 base64 编码格式的数据。

格式类似：

data:image/jpeg;base64,/9j/4AAQSkZJRgABAQAAAQABAAD/2wBDAAIBAQEBAQIBAQECAgICAgQDAgICAgUEBAMEBgUGBgYFBgYGBwkIBgcJBwYGCAsIC.....

而且有可能这个 base64 编码比上传源文件还要大。

这样做有两个缺点：

  • 多一步上传文件到第三方网站（https://httpbin.org/post），并转码 base64，其中大部分时间在这一步浪费的。
  • 服务端在接收 base64 编码内容，还要将其处理成文件进行单独保存（base64 编码内容太长，通常不会直接存入数据库），这给服务端带来不便。

还有一点就这种是必须图片和表单其他内容一起提交，有的时候上传和表单其他项分开提交。

接下来讲一下如何将图片单独上传到服务的实现步骤：

具体代码在以下项目里

github:

https://github.com/guyan0319/…

码云（国内）:

https://gitee.com/jason0319/g…

示例一、解决如下图所示的上传和删除

1、新建文件 

vue-element-admin\src\utils\global.js

内容如下 

const httphost = 'http://localhost:8090'
export {httphost}

这个是服务端的地址，可以根据需要自己调整。

2、修改上传组件代码在 SingleImage3.vue

上传图片

引入上面定义的服务器地址 

import {httphost} from '@/utils/global'

data() 增加 uploadUrl

data() {
    return {
      tempUrl: '',
      uploadUrl: httphost + '/upload/image',
      dataObj: {token: '', key:''}
    }
  },

将 

action=``"https://httpbin.org/post"

修改为 

 :action="uploadUrl"

图片上传成功 on-success 绑定的 handleImageSuccess 函数增加了 res，即服务端返回上传结果。

修改代码如下 

handleImageSuccess(res, file) {if (res.code !== 20000){
        this.$message({
          message: '上传失败',
          type: 'error',
          showClose: true
        })
        return false
      }
      this.emitInput(res.data)
    },

服务端返回的 json 格式为 

{
    "code":20000,
    "data":"http://localhost:8090/showimage?imgname=upload/20200620/tX5vS810l2Fl0K02I0YJLEjLEw9OH7hc.jpg"
}

这里需要注意 el-upload 增加 

:with-credentials='true'

支持发送 cookie 凭证信息，上传文件到服务器端需要判断验证登录。

删除图片

通过以上修改实现上传图片，接下处理上传文件删除

文件 api/article.js 增加 

export function delImage(url) {
  return request({
    url: '',
    method: 'get',
    params: {url},
    baseURL: httphost + '/del/image'
  })
}

修改 SingleImage3.vue

// 引入 delImage
import {delImage} from '@/api/article'
 
 rmImage() {delImage(this.value).then(response => {if (response.code === 20000){this.emitInput('')
          return
        }
        this.$message({
          message: '删除失败',
          type: 'error',
          showClose: true
        })
      }).catch(err => {console.log(err)
      })
    },

服务端删除文件返回 json

{"code":20000,"data":"success"}

最后贴一下 SingleImage3.vue 修改后完整的代码 

<template>
  <div class="upload-container">
    <el-upload
      :data="dataObj"
      :multiple="false"
      :show-file-list="false"
      :with-credentials='true'
      :on-success="handleImageSuccess"
      class="image-uploader"
      drag
      :action="uploadUrl"
    >
      <i class="el-icon-upload" />
      <div class="el-upload__text">
        将文件拖到此处，或 <em> 点击上传 </em>
      </div>
    </el-upload>
    <div class="image-preview image-app-preview">
      <div v-show="imageUrl.length>1" class="image-preview-wrapper">
        <img :src="imageUrl">
        <div class="image-preview-action">
          <i class="el-icon-delete" @click="rmImage" />
        </div>
      </div>
    </div>
    <div class="image-preview">
      <div v-show="imageUrl.length>1" class="image-preview-wrapper">
        <img :src="imageUrl">
        <div class="image-preview-action">
          <i class="el-icon-delete" @click="rmImage" />
        </div>
      </div>
    </div>
  </div>
</template>

<script>
import {getToken} from '@/api/qiniu'
import {delImage} from '@/api/article'
import {httphost} from '@/utils/global'
// import {Cookies} from 'js-cookie'
export default {
  name: 'SingleImageUpload3',
  props: {
    value: {
      type: String,
      default: ''
    }
  },
  data() {
    return {
      tempUrl: '',
      uploadUrl: httphost + '/upload/image',
      dataObj: {token: '', key:''}
    }
  },
  computed: {imageUrl() {return this.value}
  },
  methods: {rmImage() {delImage(this.value).then(response => {if (response.code === 20000){this.emitInput('')
          return
        }
        this.$message({
          message: '删除失败',
          type: 'error',
          showClose: true
        })
      }).catch(err => {console.log(err)
      })
    },
    emitInput(val) {this.$emit('input', val)
    },

    handleImageSuccess(res, file) {if (res.code !== 20000){
        this.$message({
          message: '上传失败',
          type: 'error',
          showClose: true
        })
        return false
      }
      this.emitInput(res.data)
    },
    beforeUpload() {
      const _self = this
      return new Promise((resolve, reject) => {getToken().then(response => {
          const key = response.data.qiniu_key
          const token = response.data.qiniu_token
          _self._data.dataObj.token = token
          _self._data.dataObj.key = key
          this.tempUrl = response.data.qiniu_url
          resolve(true)
        }).catch(err => {console.log(err)
          reject(false)
        })
      })
    }
  }
}
</script>

<style lang="scss" scoped>
@import "~@/styles/mixin.scss";
.upload-container {
  width: 100%;
  position: relative;
  @include clearfix;
  .image-uploader {
    width: 35%;
    float: left;
  }
  .image-preview {
    width: 200px;
    height: 200px;
    position: relative;
    border: 1px dashed #d9d9d9;
    float: left;
    margin-left: 50px;
    .image-preview-wrapper {
      position: relative;
      width: 100%;
      height: 100%;
      img {
        width: 100%;
        height: 100%;
      }
    }
    .image-preview-action {
      position: absolute;
      width: 100%;
      height: 100%;
      left: 0;
      top: 0;
      cursor: default;
      text-align: center;
      color: #fff;
      opacity: 0;
      font-size: 20px;
      background-color: rgba(0, 0, 0, .5);
      transition: opacity .3s;
      cursor: pointer;
      text-align: center;
      line-height: 200px;
      .el-icon-delete {font-size: 36px;}
    }
    &:hover {
      .image-preview-action {opacity: 1;}
    }
  }
  .image-app-preview {
    width: 320px;
    height: 180px;
    position: relative;
    border: 1px dashed #d9d9d9;
    float: left;
    margin-left: 50px;
    .app-fake-conver {
      height: 44px;
      position: absolute;
      width: 100%; // background: rgba(0, 0, 0, .1);
      text-align: center;
      line-height: 64px;
      color: #fff;
    }
  }
}
</style>

示例二、解决如下图所示的上传

需要修改 vue-element-adminsrccomponentsTinymcecomponentsEditorImage.vue 文件，处理方式和示例一差不多，这里只贴代码 

<template>
  <div class="upload-container">
    <el-button :style="{background:color,borderColor:color}" icon="el-icon-upload" size="mini" type="primary" @click="dialogVisible=true">
      upload
    </el-button>
    <el-dialog :visible.sync="dialogVisible">
      <el-upload
        :multiple="true"
        :file-list="fileList"
        :show-file-list="true"
        :with-credentials='true'
        :on-remove="handleRemove"
        :on-success="handleSuccess"
        :before-upload="beforeUpload"
        class="editor-slide-upload"
        :action="uploadUrl"
        list-type="picture-card"
      >
        <el-button size="small" type="primary">
          Click upload
        </el-button>
      </el-upload>
      <el-button @click="dialogVisible = false">
        Cancel
      </el-button>
      <el-button type="primary" @click="handleSubmit">
        Confirm
      </el-button>
    </el-dialog>
  </div>
</template>

<script>
// import {getToken} from 'api/qiniu'
import {delImage} from '@/api/article'
import {httphost} from '@/utils/global'
export default {
  name: 'EditorSlideUpload',
  props: {
    color: {
      type: String,
      default: '#1890ff'
    }
  },
  data() {
    return {
      dialogVisible: false,
      uploadUrl: httphost + '/upload/image',
      listObj: {},
      fileList: []}
  },
  methods: {checkAllSuccess() {return Object.keys(this.listObj).every(item => this.listObj[item].hasSuccess)
    },
    handleSubmit() {const arr = Object.keys(this.listObj).map(v => this.listObj[v])
      if (!this.checkAllSuccess()) {this.$message('Please wait for all images to be uploaded successfully. If there is a network problem, please refresh the page and upload again!')
        return
      }
      this.$emit('successCBK', arr)
      this.listObj = {}
      this.fileList = []
      this.dialogVisible = false
    },
    handleSuccess(response, file) {
      const uid = file.uid
      const objKeyArr = Object.keys(this.listObj)
      for (let i = 0, len = objKeyArr.length; i < len; i++) {if (this.listObj[objKeyArr[i]].uid === uid) {this.listObj[objKeyArr[i]].url = response.data
          // this.listObj[objKeyArr[i]].url = response.files.file
          this.listObj[objKeyArr[i]].hasSuccess = true
          return
        }
      }
    },
    handleRemove(file) {
      const uid = file.uid
      const objKeyArr = Object.keys(this.listObj)
      for (let i = 0, len = objKeyArr.length; i < len; i++) {if (this.listObj[objKeyArr[i]].uid === uid) {delImage(this.listObj[objKeyArr[i]].url).then(response => {if (response.code !== 20000) {this.$message('删除失败')
              return
            }
            delete this.listObj[objKeyArr[i]]
          }).catch(err => {console.log(err)
          })

          return
        }
      }
    },
    beforeUpload(file) {
      const _self = this
      const _URL = window.URL || window.webkitURL
      const fileName = file.uid
      this.listObj[fileName] = {}
      return new Promise((resolve, reject) => {const img = new Image()
        img.src = _URL.createObjectURL(file)
        img.onload = function() {_self.listObj[fileName] = {hasSuccess: false, uid: file.uid, width: this.width, height: this.height}
        }
        resolve(true)
      })
    }
  }
}
</script>

<style lang="scss" scoped>
.editor-slide-upload {
  margin-bottom: 20px;
  /deep/ .el-upload--picture-card {width: 100%;}
}
</style>

至此，vue-element-admin 单独上传图片实现方式就讲完了，如有任何问题或建议欢迎提 issues，

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vue.js
发表至： vue.js
2020-06-20
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