指出这段代码的错误 <template> <div class="manage"> <el-dialog title="提示" :visible.sync="dialogVisible" width="30%"> <span>这是一段信息</span> <span slot="footer" class="dialog-footer"> <el-button @click="dialogVisible = false">取 消</el-button> <el-button type="primary" @click="dialogVisible = false">确 定</el-button> </span> </el-dialog> </div> <div class="manage-header"> <el-button type="primary" @click="dialogVisible = true">+ 新增</el-button> </div> </template> <script> export default { // name: "Emp", data() { return { dialogVisible: false, primary:"", }; } } </script> <style scoped></style>

这段代码没有明确引入 Element UI 组件库，应该在 `<script>` 标签中添加 `import` 语句引入 Element UI 组件库。另外，代码中的 `el-dialog` 组件未被正确地包裹在 `el-button` 组件内，应该将 `<span slot="footer" class="dialog-footer">` 标签移动到 `el-dialog` 组件标签内，并将其中的内容用 `el-button` 组件包裹。修改后的代码如下：

<template>
  <div class="manage">
    <el-dialog title="提示" :visible.sync="dialogVisible" width="30%">
      <span>这是一段信息</span>
      <template slot="footer">
        <el-button @click="dialogVisible = false">取 消</el-button>
        <el-button type="primary" @click="dialogVisible = false">确 定</el-button>
      </template>
    </el-dialog>
  </div>
  <div class="manage-header">
    <el-button type="primary" @click="dialogVisible = true">+ 新增</el-button>
  </div>
</template>

<script>
import { ElButton, ElDialog } from 'element-ui';

export default {
  components: {
    ElButton,
    ElDialog,
  },
  data() {
    return {
      dialogVisible: false,
      primary: "",
    };
  },
};
</script>

<style scoped></style>