效果

完整代码见文末

实现思路

1. 使用两个表单分别用于实现修改和新增处理。

2. 通过一个editIndex变量判断是否是编辑状态来决定是否展示输入框，当点击指定行的修改后进行设置即可：

   <el-table-columnv-for="(column, index) in columns":key="index":label="column.label":prop="column.prop"align="center"><template #default="{ row, $index }"><div v-if="$index === editIndex" class="validate-info"><el-form-item :prop="column.prop"><el-input v-model="editRow[column.prop]"/></el-form-item></div><span v-else><span>{{ row[column.prop] }}</span></span></template>
   </el-table-column>
   

   edit(row, index) {if (this.editIndex > -1) {this.$message.warning('请先完成修改中的行')return}this.editRow = {...row}this.editIndex = index
   }
   

3. 通过隐藏表头实现新增表格和修改表格的合并，同时表格数据只有addRow：

   <el-table :data="[addRow]" :show-header="false">...
   </el-table>
   

实现细节讲解

1. 当无数据时只展示新增行：

   

   通过设置以下样式即可：

   /deep/ .el-table__empty-block {display: none;
   }
   

2. 新增或者修改数据行时增加行高用于显示校验信息：

   

   行高通过以下样式进行控制，不处于新增或者修改状态时设置为 0 即可：

   .add-table /deep/ .el-form-item {margin: 18px 0;
   }
   

   为了在修改时只设置修改行的行高，只需要只对输入框绑定样式即可：

   <div v-if="$index === editIndex" class="validate-info"><el-form-item :prop="column.prop"><el-input v-model="editRow[column.prop]"/></el-form-item>
   </div>
   

完整代码

<template><div class="app"><el-formref="editableForm":model="editRow":rules="rules"label-width="0":show-message="true"class="editable-table"><el-table :data="tableData"><el-table-columnv-for="(column, index) in columns":key="index":label="column.label":prop="column.prop"align="center"><template #default="{ row, $index }"><div v-if="$index === editIndex" class="validate-info"><el-form-item :prop="column.prop"><el-input v-model="editRow[column.prop]"/></el-form-item></div><span v-else><span>{{ row[column.prop] }}</span></span></template></el-table-column><el-table-column label="操作" width="200" align="center"><template #default="{ row, $index }"><el-form-item><template v-if="$index === editIndex"><el-button type="success" size="mini" plain @click="save">保存</el-button><el-button type="info" size="mini" plain @click="cancel">取消</el-button></template><template v-else><el-buttontype="primary"size="mini"plain@click="edit(row, $index)">修改</el-button><el-popconfirmtitle="是否确认删除？"@confirm="deleteRow($index)"style="margin-left: 10px;"><el-button slot="reference" type="danger" size="mini" plain>删除</el-button></el-popconfirm></template></el-form-item></template></el-table-column></el-table></el-form><el-formref="addForm":model="addRow":rules="rules"label-width="0":show-message="true"class="add-table"><el-table :data="[addRow]" :show-header="false"><el-table-columnv-for="(column, index) in columns":key="index":label="column.label":prop="column.prop"align="center"><template #default="{ row }" class="validate-info"><div class="validate-info"><el-form-item :prop="column.prop"><el-input v-model="addRow[column.prop]"/></el-form-item></div></template></el-table-column><el-table-column label="操作" width="200px" align="center"><template #default="{ row }"><el-form-item><el-button type="success" size="mini" plain @click="add(row)">新增</el-button></el-form-item></template></el-table-column></el-table></el-form></div>
</template><script>
export default {data() {return {// 表格数据tableData: [{username: '张三',address: '北京'},{username: '李四',address: '上海'}],//配置列columns: [{label: '用户名',prop: 'username'},{label: '地址',prop: 'address'}],// 规则rules: {username: [{required: true, message: '请输入用户名', trigger: 'blur'}],address: [{required: true, message: '请输入地址', trigger: 'blur'}],},// 当前编辑行下标editIndex: -1,// 当前编辑行editRow: {username: '',address: ''},// 新增行addRow: {username: '',address: ''}}},methods: {save() {this.$refs.editableForm.validate((valid) => {if (valid) {this.tableData.splice(this.editIndex, 1, { ...this.editRow })this.editIndex = -1this.$message.success('修改成功')}return valid})},cancel() {this.editIndex = -1},edit(row, index) {if (this.editIndex > -1) {this.$message.warning('请先完成修改中的行')return}this.editRow = {...row}this.editIndex = index},add(row) {if (this.editIndex > -1) {this.$message.warning('请先完成修改中的行')return}this.$refs.addForm.validate((valid) => {if (valid) {this.addRow = {}this.tableData.push({ ... row})this.$message.success('新增成功')}return valid})},deleteRow(index) {this.tableData.splice(index, 1)this.$message.success('删除成功!');}}
}
</script><style scoped lang="less">
.app {padding: 20px;/deep/ .el-form-item {margin-bottom: 0;}
}.validate-info {/deep/ .el-form-item {margin: 18px 0;}
}.editable-table {/deep/ .el-table__empty-block {display: none;}
}.editable-table, .add-table {width: 60%;margin: 0 auto;
}
</style>