Vue项目中文件导入和导出使用比较频繁，这里把最常用的布局和实现代码记录下来，避免以后频繁造轮子。

1、导出一般就是在列表中选择几条数据，然后点击导出按钮把选中的数据下载下来；导入的话一般会有一个单独的弹框页面，需要先选择文件，然后统一导入。

导入弹框 

2、导入弹框对应的页面代码：

<!--
 * @Author: lujinwei
 * @Date: 2022-08-13 17:29:58
 * @LastEditTime: 2022-08-30 14:22:20
 * @Description: 导入数据
-->
<template>
  <el-dialog
    title="导入"
    :visible.sync="dialogVisible"
    width="660px"
    :close-on-click-modal="false"
    :before-close="onClose"
    @closed="onAfterClose"
  >
    <div
      v-loading="loading"
      class="dialog-content"
    >
      <el-form
        ref="formRef"
        :model="formData"
        label-width="80px"
      >
        <el-form-item
          label="选择文件"
          prop="fileList"
        >
          <el-upload
            ref="upload"
            action="#"
            :accept="extAcceptStr"
            :auto-upload="false"
            :limit="limit"
            :file-list="formData.fileList"
            :on-change="onFileChange"
            :on-remove="onFileMove"
            :on-exceed="onFileExceed"
          >
            <div class="select-file">
              <p class="select-p">
                请选择上传文件
              </p>
              <el-button
                size="small"
                type="primary"
              >
                选取文件
              </el-button>
            </div>

            <div
              slot="tip"
              class="el-upload__tip"
            >
              {{ `支持${extAcceptStr}格式的文件，大小不能超过10M` }}
            </div>
          </el-upload>

          <el-button
            type="text"
            @click="onDownload"
          >
            模板下载
          </el-button>
        </el-form-item>
      </el-form>
    </div>

    <template slot="footer">
      <el-button
        type="primary"
        :loading="!!loading"
        :disabled="!formData.fileList.length > 0"
        @click="onSubmit"
      >
        导入
      </el-button>
      <el-button @click="dialogVisible = false">
        取消
      </el-button>
    </template>
  </el-dialog>
</template>

<script>
export default {
  props: {
    loading: Boolean,
    limit: { //限制文件上传个数
      type: Number,
      default: 1,
    },
  },

  data () {
    return {
      // # config
      extAccept: ["xls", "xlsx"],
      // # state
      dialogVisible: false,
      // # data
      formData: {
        fileList: [],
      },
    }
  },

  computed: {
    extAcceptStr () {
      return this.extAccept.map(ext => `.${ext}`).join(",")
    },
  },
  methods: {
    onShow () {
      this.dialogVisible = true
    },
    onClose () {
      this.dialogVisible = false
    },
    onAfterClose () {
      this.formData = {
        fileList: [],
      }
    },
    // # upload
    // 校验
    validateFile (file) {
      if (!file) return "至少添加一个文件！"
      const ext = (file.name || "").split(".").reverse()[0]
      if (!this.extAccept.includes(ext))
        return `仅支持${this.extAcceptStr}格式的文件`
      return ""
    },

    onFileChange (file, fileList) {
      const errMsg = this.validateFile(file)
      if (errMsg) {
        this.$message.warning(errMsg)
        this.formData.fileList.splice(0, 1)
      } else {
        this.formData.fileList = fileList
      }
    },
    onFileMove (file, fileList) {
      this.formData.fileList = fileList
    },
    onFileExceed () {
      this.$message.warning(`仅允许上传 ${this.limit} 个文件！`)
    },

    // # emit
    // 模板下载
    onDownload () {
      this.$emit("download")
    },
    // 导入
    onSubmit () {
      this.$emit("submit", this.formData)
    },
  },
}
</script>

<style lang="less" scope>
.dialog-content {
  height: 300px;
  padding: 16px;

  .select-file {
    display: flex;
    height: 36px;

    .select-p {
      width: 380px;
      height: 32px;
      line-height: 32px;
      border: 1px solid #dcdfe6;
      text-align: left;
      padding-left: 8px;
      color: #636fa1;
      font-size: 12px;
    }
  }
}
</style>

 3、在父布局中使用弹框组件：

①导入

②布局中使用 

<dialog-import
    ref="dialogImportRef"
    :loading="importLoading"
    @download="onTempDownload"
    @submit="onImportSubmit"
/>

 ③子组件对应的方法

-----------------------------------------------  模板下载相关  -------------------------------------------

//模板下载
onTempDownload () {
  inlivePersonApi.downloadTemplate('1').then(res => {
    console.log(res)
    saveBlobToFile(res)
  })
}

// 下载人员导入修改模板
downloadTemplate: (templateKey) => http.getBlob(`/v1/apartment/user/downloadTemplate?templateKey=${templateKey}`)

saveBlobToFile是在公共方法中封装的下载方法：

export function saveBlobToFile (res, filename) {
  if (res.headers['content-disposition']) {
    var fileName = decodeURIComponent(res.headers['content-disposition'].replace('attachment;filename=', ''))
    fileName = decodeURIComponent(fileName)
    var blob = res.data
    // var blob = new Blob([res.data], {
    //   type: 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'
    // })
    if (navigator.msSaveBlob) {
      navigator.msSaveBlob(blob, fileName)
    } else {
      const oA = document.createElement('a')
      try {
        oA.href = URL.createObjectURL(blob)
      } catch (err) {
        const binaryData = []
        binaryData.push(blob)
        oA.href = window.URL.createObjectURL(new Blob(binaryData, { type: 'application/zip' }))
      }
      oA.download = filename || fileName
      oA.click()
    }
  }
}

-----------------------------------------------  导入相关  -------------------------------------------

async onImportSubmit ({ fileList }) {
  this.importLoading = true
  let fd = new FormData()
  fd.append('excelFile', fileList[0].raw)
  inlivePersonApi.importExcel(fd).then(res => {
    this.importLoading = false
    if (res.success) {
      this.$refs.dialogImportRef.onClose()
      this.pageParams.pageNo = 1
      this.requestTableData()
      this.$message({
        message: '导入成功',
        type: 'success'
      })
    }
  })
}

// 人员导入
importExcel: params => http.post('/v1/apartment/user/importExcel', params)

4、导出业务其实和上面的模板下载业务一样，也是通过接口获取数据，然后通过文件形式下载下来。