vue2中通过tab切换表格el-table-column使用if判断为什么切换会出现问题

在Vue2中使用if判断切换表格el-table-column可能会出现问题是因为Vue2中使用v-if指令进行条件渲染时，如果条件为false，则会将对应的DOM元素从DOM树中移除，如果条件为true，则会将对应的DOM元素添加到DOM树中。而在el-table-column中，如果某一列被隐藏掉，则该列的宽度也会被隐藏掉，从而导致表格的列宽出现问题。

如果要实现表格列的动态切换，建议使用Vue2中的v-show指令，该指令将会将对应的DOM元素隐藏，但是不会将其从DOM树中移除，从而保证了表格列的宽度不会出现问题。

相关问题

用vue加element ui写一个tab切换的表格加表单页面

好的，下面是一个简单的示例代码：

<template>
  <div>
    <el-tabs v-model="activeTab">
      <el-tab-pane label="表格">
        <el-table :data="tableData">
          <el-table-column prop="name" label="姓名"></el-table-column>
          <el-table-column prop="age" label="年龄"></el-table-column>
          <el-table-column prop="gender" label="性别"></el-table-column>
        </el-table>
      </el-tab-pane>
      <el-tab-pane label="表单">
        <el-form ref="form" :model="formData" :rules="rules" label-width="80px">
          <el-form-item label="姓名" prop="name">
            <el-input v-model="formData.name"></el-input>
          </el-form-item>
          <el-form-item label="年龄" prop="age">
            <el-input v-model.number="formData.age"></el-input>
          </el-form-item>
          <el-form-item label="性别" prop="gender">
            <el-radio-group v-model="formData.gender">
              <el-radio label="男"></el-radio>
              <el-radio label="女"></el-radio>
            </el-radio-group>
          </el-form-item>
          <el-form-item>
            <el-button type="primary" @click="submitForm">提交</el-button>
            <el-button @click="resetForm">重置</el-button>
          </el-form-item>
        </el-form>
      </el-tab-pane>
    </el-tabs>
  </div>
</template>

<script>
export default {
  data() {
    return {
      activeTab: '表格',
      tableData: [
        { name: '张三', age: 20, gender: '男' },
        { name: '李四', age: 25, gender: '女' },
        { name: '王五', age: 30, gender: '男' },
      ],
      formData: {
        name: '',
        age: '',
        gender: '',
      },
      rules: {
        name: [
          { required: true, message: '请输入姓名', trigger: 'blur' },
        ],
        age: [
          { required: true, message: '请输入年龄', trigger: 'blur' },
          { type: 'number', message: '年龄必须为数字值', trigger: 'blur' },
          { validator: this.checkAge, trigger: 'blur' },
        ],
        gender: [
          { required: true, message: '请选择性别', trigger: 'change' },
        ],
      },
    };
  },
  methods: {
    submitForm() {
      this.$refs.form.validate(valid => {
        if (valid) {
          console.log('表单验证通过');
        } else {
          console.log('表单验证失败');
        }
      });
    },
    resetForm() {
      this.$refs.form.resetFields();
    },
    checkAge(rule, value, callback) {
      if (value < 18 || value > 60) {
        callback(new Error('年龄必须在18岁到60岁之间'));
      } else {
        callback();
      }
    },
  },
};
</script>

在这个示例中，我们使用了 Element UI 提供的 `el-tabs` 和 `el-tab-pane` 组件来实现标签页切换功能。在第一个标签页中，我们使用了 `el-table` 和 `el-table-column` 组件来展示表格数据；在第二个标签页中，我们使用了 `el-form`、`el-form-item`、`el-input` 和 `el-radio-group` 组件来实现表单功能。同时，在表单中我们还使用了 Element UI 提供的表单验证功能，通过 `rules` 属性来设置表单验证规则。在表单验证通过后，我们可以将表单数据提交到后端进行处理。

将以下vue+element ui代码转换成纯html+element ui代码：<template> <el-tabs v-model="activeName" class="demo-tabs" @tab-click="handleClick"> <el-tab-pane label="User" name="first"> <el-table :data="filterTableData" style="width: 100%"> <el-table-column label="Date" prop="date" /> <el-table-column label="Name" prop="name" /> <el-table-column align="right"> <template #header> <el-input v-model="search" size="small" placeholder="Type to search" /> </template> <template #default="scope"> <el-button size="small" @click="handleEdit(scope.$index, scope.row)" >Edit</el-button > <el-button size="small" type="danger" @click="handleDelete(scope.$index, scope.row)" >Delete</el-button > </template> </el-table-column> </el-table> </el-tab-pane> <el-tab-pane label="Config" name="second"> <el-table :data="filterTableData" style="width: 100%"> <el-table-column label="Date" prop="date" /> <el-table-column label="Name" prop="name" /> <el-table-column align="right"> <template #header> <el-input v-model="search" size="small" placeholder="Type to search" /> </template> <template #default="scope"> <el-button size="small" @click="handleEdit(scope.$index, scope.row)" >Edit</el-button > <el-button size="small" type="danger" @click="handleDelete(scope.$index, scope.row)" >Delete</el-button > </template> </el-table-column> </el-table></el-tab-pane> <el-tab-pane label="Role" name="third"> <el-table :data="filterTableData" style="width: 100%"> <el-table-column label="Date" prop="date" /> <el-table-column label="Name" prop="name" /> <el-table-column align="right"> <template #header> <el-input v-model="search" size="small" placeholder="Type to search" /> </template> <template #default="scope"> <el-button size="small" @click="handleEdit(scope.$index, scope.row)" >Edit</el-button > <el-button size="small" type="danger" @click="handleDelete(scope.$index, scope.row)" >Delete</el-button > </template> </el-table-column> </el-table></el-tab-pane> <el-tab-pane label="Task" name="fourth"> <el-table :data="filterTableData" style="width: 100%"> <el-table-column label="Date" prop="date" /> <el-table-column label="Name" prop="name" /> <el-table-column align="right"> <template #header> <el-input v-model="search" size="small" placeholder="Type to search" /> </template> <template #default="scope"> <el-button size="small" @click="handleEdit(scope.$index, scope.row)" >Edit</el-button > <el-button size="small" type="danger" @click="handleDelete(scope.$index, scope.row)" >Delete</el-button > </template> </el-table-column> </el-table></el-tab-pane> </el-tabs> </template> <script lang="ts" setup> import { computed, ref } from 'vue' interface User { date: string name: string address: string } const search = ref('') const filterTableData = computed(() => tableData.filter( (data) => !search.value || data.name.toLowerCase().includes(search.value.toLowerCase()) ) ) const handleEdit = (index: number, row: User) => { console.log(index, row) } const handleDelete = (index: number, row: User) => { console.log(index, row) } const tableData: User[] = [ { date: '2016-05-03', name: 'Tom', address: 'No. 189, Grove St, Los Angeles', }, { date: '2016-05-02', name: 'John', address: 'No. 189, Grove St, Los Angeles', }, { date: '2016-05-04', name: 'Morgan', address: 'No. 189, Grove St, Los Angeles', }, { date: '2016-05-01', name: 'Jessy', address: 'No. 189, Grove St, Los Angeles', }, ] </script> <style> .demo-tabs > .el-tabs__content { padding: 32px; color: #6b778c; font-size: 32px; font-weight: 600; } </style>

以下是转换后的纯HTML+Element UI代码：

<div class="demo-tabs el-tabs">
  <div class="el-tabs__header">
    <div class="el-tabs__nav-wrap">
      <div role="tab" aria-controls="pane-first" :aria-selected="activeName==='first' ? 'true' : 'false'" class="el-tabs__item" :class="{ 'is-active': activeName==='first' }" @click="activeName='first'">User</div>
      <div role="tab" aria-controls="pane-second" :aria-selected="activeName==='second' ? 'true' : 'false'" class="el-tabs__item" :class="{ 'is-active': activeName==='second' }" @click="activeName='second'">Config</div>
      <div role="tab" aria-controls="pane-third" :aria-selected="activeName==='third' ? 'true' : 'false'" class="el-tabs__item" :class="{ 'is-active': activeName==='third' }" @click="activeName='third'">Role</div>
      <div role="tab" aria-controls="pane-fourth" :aria-selected="activeName==='fourth' ? 'true' : 'false'" class="el-tabs__item" :class="{ 'is-active': activeName==='fourth' }" @click="activeName='fourth'">Task</div>
    </div>
  </div>
  <div class="el-tabs__content">
    <div role="tabpanel" aria-hidden="false" id="pane-first" class="el-tab-pane" :class="{ 'is-active': activeName==='first' }">
      <table class="el-table" style="width: 100%">
        <thead class="el-table__header">
          <tr>
            <th class="el-table_1_column_1">Date</th>
            <th class="el-table_1_column_2">Name</th>
            <th class="el-table_1_column_3">Operation</th>
          </tr>
        </thead>
        <tbody class="el-table__body">
          <tr v-for="(item, index) in filterTableData" :key="index">
            <td>{{ item.date }}</td>
            <td>{{ item.name }}</td>
            <td class="el-table_1_column_3">
              <button class="el-button el-button--small" @click="handleEdit(index, item)">Edit</button>
              <button class="el-button el-button--small el-button--danger" @click="handleDelete(index, item)">Delete</button>
            </td>
          </tr>
        </tbody>
      </table>
    </div>
    <div role="tabpanel" aria-hidden="true" id="pane-second" class="el-tab-pane" :class="{ 'is-active': activeName==='second' }">
      <table class="el-table" style="width: 100%">
        <thead class="el-table__header">
          <tr>
            <th class="el-table_2_column_1">Date</th>
            <th class="el-table_2_column_2">Name</th>
            <th class="el-table_2_column_3">Operation</th>
          </tr>
        </thead>
        <tbody class="el-table__body">
          <tr v-for="(item, index) in filterTableData" :key="index">
            <td>{{ item.date }}</td>
            <td>{{ item.name }}</td>
            <td class="el-table_2_column_3">
              <button class="el-button el-button--small" @click="handleEdit(index, item)">Edit</button>
              <button class="el-button el-button--small el-button--danger" @click="handleDelete(index, item)">Delete</button>
            </td>
          </tr>
        </tbody>
      </table>
    </div>
    <div role="tabpanel" aria-hidden="true" id="pane-third" class="el-tab-pane" :class="{ 'is-active': activeName==='third' }">
      <table class="el-table" style="width: 100%">
        <thead class="el-table__header">
          <tr>
            <th class="el-table_3_column_1">Date</th>
            <th class="el-table_3_column_2">Name</th>
            <th class="el-table_3_column_3">Operation</th>
          </tr>
        </thead>
        <tbody class="el-table__body">
          <tr v-for="(item, index) in filterTableData" :key="index">
            <td>{{ item.date }}</td>
            <td>{{ item.name }}</td>
            <td class="el-table_3_column_3">
              <button class="el-button el-button--small" @click="handleEdit(index, item)">Edit</button>
              <button class="el-button el-button--small el-button--danger" @click="handleDelete(index, item)">Delete</button>
            </td>
          </tr>
        </tbody>
      </table>
    </div>
    <div role="tabpanel" aria-hidden="true" id="pane-fourth" class="el-tab-pane" :class="{ 'is-active': activeName==='fourth' }">
      <table class="el-table" style="width: 100%">
        <thead class="el-table__header">
          <tr>
            <th class="el-table_4_column_1">Date</th>
            <th class="el-table_4_column_2">Name</th>
            <th class="el-table_4_column_3">Operation</th>
          </tr>
        </thead>
        <tbody class="el-table__body">
          <tr v-for="(item, index) in filterTableData" :key="index">
            <td>{{ item.date }}</td>
            <td>{{ item.name }}</td>
            <td class="el-table_4_column_3">
              <button class="el-button el-button--small" @click="handleEdit(index, item)">Edit</button>
              <button class="el-button el-button--small el-button--danger" @click="handleDelete(index, item)">Delete</button>
            </td>
          </tr>
        </tbody>
      </table>
    </div>
  </div>
</div>

需要注意的是，Element UI的CSS样式需要在HTML文件中引入。此外，上述代码中的`activeName`、`search`、`filterTableData`、`handleEdit`和`handleDelete`需要在JavaScript中定义和实现。