【antd Vue】封装upload图片上传组件（返回Base64）

太过爱你忘了你带给我的痛 2022-11-04 05:52 397阅读 0赞

> 最近需要把上传的图片信息存储到数据库，以base64的方式，需要重新封装一下antd的upload组件

### 1. 使用方法 ###

引入组件然后配置一下即可使用，配置项包括

*  defaultImageList，需要回显的图片（必传），\[ url1, url2 \]
 *  fileTypeList ，文件格式（可选），默认不做限制
 *  limitSize ，单个图片大小限制（可选），单位MB
 *  limitNum ，上传图片个数限制（可选），默认200个
 *  multiple ，是否可以多选（可选），默认否
 *  disabled ，是否禁用（可选），默认否

1.  引用组件

<template>
      <div>
        <b-upload-image-base64 ref="bUploadImageBase64" :limitNum="1" @change="change" :defaultImageList="data" />
      </div>
    </template>
    <script>
      import bUploadImageBase64 from '@/components/BUploadImageBase64'
      export default {
        components: {
          bUploadImageBase64
        },
        data() {
          return {
            data: ['https://zos.alipayobjects.com/rmsportal/jkjgkEfvpUPVyRjUImniVslZfWPnJuuZ.png'],
            defaultImageList: []
          };
        },
        methods: {
          change(e) {
            console.log('e', e)
          }
        },
      };
    </script>
    <style>
    
    </style>

1.  组件

<template>
      <div class="clearfix">
        <a-upload
          :beforeUpload="beforeImageUpload"
          list-type="picture-card"
          :file-list="imageList"
          :multiple="multiple"
          :disabled="disabled"
          @change="handleImageChange"
          @preview="handlePreview"
          :custom-request="customRequest"
        >
          <div v-if="imageList.length < limitNum && !disabled">
            <a-icon type="plus"/>
            <div class="ant-upload-text">上传</div>
          </div>
        </a-upload>
        <a-modal :visible="previewVisible" :footer="null" @cancel="handleCancel">
          <img alt="example" style="width: 100%" :src="previewImage"/>
        </a-modal>
      </div>
    </template>
    <script>
      function getBase64(file) {
        return new Promise((resolve, reject) => {
          const reader = new FileReader()
          reader.readAsDataURL(file)
          reader.onload = () => resolve(reader.result)
          reader.onerror = error => reject(error)
        })
      }
    
      export default {
        props: {
          defaultImageList: {
            type: Array,
            default: function() {
              return []
            },
            required: true
          },
          fileTypeList: {
            type: Array,
            default: function() {
              return []
            },
            required: false
          },
          limitSize: {
            type: Number,
            default: 5,
            required: false
          },
          limitNum: {
            type: Number,
            default: 20,
            required: false
          },
          multiple: {
            type: Boolean,
            default: false,
            required: false
          },
          disabled: {
            type: Boolean,
            default: false,
            required: false
          }
        },
        data() {
          return {
            previewVisible: false,
            previewImage: '',
            imageList: []
          }
        },
        watch: {
          defaultImageList(newVal) {
            this.imageList = this.handleData(newVal)
          }
        },
        created() {
          this.imageList = this.handleData(this.defaultImageList)
        },
        methods: {
          // ---------------------------------------------img--start
          beforeImageUpload(file) {
            return new Promise((resolve, reject) => {
              if (this.fileTypeList.length > 0) {
                const index = this.fileTypeList.indexOf(file.type)
                if (index > 0) {
                  this.$message.error(`您只能上传${this.fileTypeList[index]}文件`)
                }
              }
              const limitSize = file.size / 1024 / 1024 < this.limitSize
              if (!limitSize) {
                this.$message.error(`文件大小不能大于${this.limitSize}MB`)
                return reject(new Error(`文件大小不能大于${this.limitSize}MB`))
              }
              return resolve(true)
            })
          },
          async handlePreview(file) {
            if (!file.url && !file.preview) {
              file.preview = await getBase64(file.originFileObj)
            }
            this.previewImage = file.url || file.preview
            this.previewVisible = true
          },
          handleCancel() {
            this.previewVisible = false
          },
          customRequest({ action, file, onSuccess, onError, onProgress }) {
            new Promise(resolve => {
              const fileReader = new FileReader()
              fileReader.readAsDataURL(file)
              fileReader.onload = () => {
                let index = {
                  uid: this.genId(5),
                  name: file.name,
                  status: 'done',
                  url: fileReader.result
                }
                this.imageList = [...this.imageList.filter(item => item.status === 'done'), index]
                this.$message.success('文件上传成功！')
                this.handleChange()
                resolve(fileReader.result)
              }
            })
          },
          handleImageChange(info) {
            let fileList = [...info.fileList]
            this.imageList = fileList
            this.handleChange()
          },
          handleChange() {
            let index = this.imageList.filter(item => item.url).map(item => {
              return item.url
            })
            this.$emit('change', index ? index : [])
          },
          genId(length) {
            return Number(Math.random().toString().substr(3, length) + Date.now()).toString(36)
          },
          handleData (list) {
            return list.map(item => {
              let index = this.genId(5)
              return {
                uid: index,
                name: index,
                status: 'done',
                url: item
              }
            })
          }
          // ---------------------------------------------img--end
        }
      }
    </script>
    <style>
      /* you can make up upload button and sample style by using stylesheets */
      .ant-upload-select-picture-card i {
        font-size: 32px;
        color: #999;
      }
    
      .ant-upload-select-picture-card .ant-upload-text {
        margin-top: 8px;
        color: #666;
      }
    </style>

### 2. 封装遇到的坑 ###

因为是自己实现上传逻辑需要使用属性`:custom-request="customRequest"`  
组件的运行顺序是`beforeImageUpload`\->`customRequest`

1.  一开始的校验需要写在beforeImageUpload中，主要是验证文件格式，文件大小
2.  然后进入自定义的上传逻辑，这里主要是读取图片为base64，然后放入回显的数组中，这样组件就可以显示上传的图片了，此时还需要回调base64
3.  handleChange方法主要是删除图片使用，需要过滤出非undefined的，剩余的图片并回传base64