<template>
  <span style="margin-right:10px">
    <input class="input-file" ref="input" id="file" type="file" @change="exportData"
      accept=".csv, application/vnd.openxmlformats-officedocument.spreadsheetml.sheet, application/vnd.ms-excel" />
    <el-button type="primary" @click="btnClick">
      导入
    </el-button>
  </span>
</template>
 
<script>
// 引入组件
import XLSX from "xlsx";
export default {
  data() {
    return {};
  },
  methods: {
    btnClick() {
      // 点击事件
      // document.querySelector(".input-file").click();
      document.getElementById('file').click();
    },
    exportData(event) {
      if (!event.currentTarget.files.length) {
        return;
      }
      const that = this;
      // 拿取文件对象
      var f = event.currentTarget.files[0];
      // 用FileReader来读取
      var reader = new FileReader();
      // 重写FileReader上的readAsBinaryString方法
      FileReader.prototype.readAsBinaryString = function (f) {
        var binary = "";
        var wb; // 读取完成的数据
        var outdata; // 你需要的数据
        var reader = new FileReader();
        reader.onload = function () {
          // 读取成Uint8Array，再转换为Unicode编码（Unicode占两个字节）
          var bytes = new Uint8Array(reader.result);
          var length = bytes.byteLength;
          for (var i = 0; i < length; i++) {
            binary += String.fromCharCode(bytes[i]);
          }
          // 接下来就是xlsx了，具体可看api
          wb = XLSX.read(binary, {
            type: "binary"
          });
          outdata = XLSX.utils.sheet_to_json(wb.Sheets[wb.SheetNames[0]]);
          // 自定义方法向父组件传递数据
          that.$emit("getResult", outdata);
          that.$refs.input.value = null
        };
        reader.readAsArrayBuffer(f);
      };
      reader.readAsBinaryString(f);
    }
  }
};
</script>
 
<style>
.input-file {
  display: none;
}
</style>