ElementUI-tree拖拽功能与节点自定义-编程知识

前言

在管理端会遇到多分类时，要求有层次展示出来，并且每个分类有额外的操作。例如：添加分类、编辑分类、删除、拖到分类等。

下面将会记录这样的一个需求实习过程。

了解需求

分类展示按层级展示
分类根据特定的参数展示可以操作的按钮，分类的操作有增、删、改
分类还支持拖拽功能，并不是所有的分类都支持拖拽
点分类去执行别的操作。例如：刷新数据（不实现）
增加分类之后刷新分类数据，当前选择的分类为增加的分类
删除分类后回到上一级分类
右击分类和点击操作按钮均可以弹出操作弹窗
点击分类前的箭头可展开和折叠分类

效果图

分类展示

分类操作的弹窗

组件库

采用ElementUI 中的 Tree树形控件、Dropdown下拉菜单

Tree树形控件：Element - The world's most popular Vue UI framework
Dropdown下拉菜单dropdown：Element - The world's most popular Vue UI framework

开始编码

搭建tree 组件

html 部分：

<el-tree :data="classifyData" node-key="id" draggable ref="tree" :accordion="false" auto-expand-parent :default-expanded-keys="[checkedId]" :props="defaultProps":allow-drop="allowDrop" :allow-drag="allowDrag"@node-drag-start="handleDragStart" @node-drop="handleDrop"@node-click="nodeClick" @node-contextmenu="rightClick":show-checkbox="false" :check-strictly="true"  ><div class="custom-tree-node" slot-scope="{ node, data }"><span>{{ data.name }}</span> <span><el-dropdown type="primary" trigger="click" :ref="'messageDrop'+data.id" @visible-change="controlCheckedKeys"><span class="el-dropdown-link" @click.stop="setSeletKey(data.id)">  <img src="~@/../more-active.png" v-if="checkedKeys == data.id"  class="myicon-opt" /> <img src="~@/../more.png" v-else class="myicon-opt" /></span><el-dropdown-menu slot="dropdown"><el-dropdown-item v-if="data.is_add_classify"><div @click="openClassify(data.id,'新增子分类')"><img src="~@/../add.png" class="myicon-opt"/> 新增子分类</div></el-dropdown-item><el-dropdown-item v-if="data.is_edit_sort"><div @click="editClassify(data)"> <img src="~@/../edit.png" class="myicon-opt" /> 修改</div></el-dropdown-item><el-dropdown-item v-if="data.is_edit_sort"><div @click="delBefore(data.id,data.parent_id)"><img src="~@/../del.png" class="myicon-opt" />删除</div></el-dropdown-item></el-dropdown-menu></el-dropdown></span></div></el-tree>

<style lang="stylus" scoped>
.active{background: #F2F6F9;color: #409EFF;
}
.classify{padding : 0 16px;height: 40px;font-family: PingFangSC-Medium;font-weight: 500;font-size: 15px; line-height:40px;
}.el-tree ::v-deep {.el-tree-node__content{ @extend .classify;&:hover{@extend .active; }.el-tree-node__expand-icon.is-leaf{// display:nonemargin-left:-12px}}.is-checked > .el-tree-node__content{@extend .active;} 
} 
.custom-tree-node{display: flex;justify-content: space-between;width: 100%;
}
.myicon-opt{vertical-align: middle;width: 16px;height: 16px;
} 
</style>

<script>export default {props:{activeId:{type:[String,Number],default:''},classifyData:{type:Array,default:[]}},watch:{activeId: {handler(v,o){// v 值为0时, 0 == '' 值为trueif (typeof v == 'number') {this.checkedId = v this.$nextTick(()=>{this.$refs.tree.setCheckedKeys([v])}) }},immediate:true,deep:true },},data() {return {checkedId:'', checkedKeys:'', defaultProps: {children: 'child',label: 'name'},classifyCofig:{flag:false,Id: '',title:'',value:''}, }},methods: { // 点击分类名称nodeClick(data,node){ this.checkedId = data.id  this.$refs.tree.setCheckedKeys([data.id]) node.expanded = truethis.$emit('selectId',data.id)// console.log('node',data.id,node.parent)let addId  = [ data.id]if(node.parent.parent != null)  this.selectNode(addId,node.parent)// console.log('addId',addId)this.$emit('selectaddId', addId)},// 获取多层级的父类id加入到数组下标为0的位置selectNode(id,node){ id.unshift(node.data.id)if(node.parent.parent != null){this.selectNode(id,node.parent)} },// 右击分类rightClick(event,data, Node, element){ setTimeout(()=>{this.checkedKeys = data.id this.$refs['messageDrop'+data.id].show() })},// 点击操作按钮setSeletKey(k){ setTimeout(()=>{this.checkedKeys = k})},// 下拉菜单的异步监听，打开（true）还是隐藏(flase)controlCheckedKeys(flag){  if(!flag){this.checkedKeys = ''}},// 节点开始拖拽时触发的事件handleDragStart(node) {if(!node.data.is_edit_sort){return false} }, // 拖拽成功完成时触发的事件handleDrop(draggingNode, dropNode, dropType) {if(dropType == 'none') return // 准备排序参数可自行更改let params = {pk1: draggingNode.data.id,pk2: dropNode.data.id,direction:dropType == 'before' ? -1 : 1}this.orderClassify(params)}, /** *  拖拽时判定目标节点能否被放置。* @param {*} draggingNode * @param {*} dropNode * @param {*} type 参数有三种情况：'prev'、'inner' 和 'next'，分别表示放置在目标节点前、插入至目标节点和放置在目标节点后*/allowDrop(draggingNode, dropNode, type) {if (draggingNode.level === dropNode.level) { if (draggingNode.data.parent_id === dropNode.data.parent_id && dropNode.data.is_edit_sort) {// 向上拖拽 || 向下拖拽return type === "prev" || type === "next"}} else {// 不同级进行处理return false}},//判断节点能否被拖拽allowDrag(draggingNode) {if(!draggingNode.data.is_edit_sort){return false}return true }, async orderClassify(params){// 发送排序请求}, setClassCofig(flag,id,title,value){this.classifyCofig['flag'] = flagthis.classifyCofig['Id'] = idthis.classifyCofig['title'] = titlethis.classifyCofig['value'] = value},openClassify(pid,txt){this.setClassCofig(true,pid, txt ? txt : '新增分类','')   },editClassify(row){this.setClassCofig(true,row.id, '修改分类', row.name) }, closeAdd(){this.setClassCofig(false,'', '', '')},// 新增/修改分类async sureClassify(params){ let {value,Id} = this.classifyCofig// 通过value的值判断当前是新增还是修改// 刷新分类，cid 新分类的idlet refresh = { }if(value){ refresh.flag = false}else{ refresh.flag = true}  // 准备参数,发送请求// 请求成功后执行this.setClassCofig(false,'', '', '')refresh.cid = value? this.checkedId : res.data.data.idthis.$emit('refreshClass',refresh)},//判断分类是否可以删除async delBefore(id,pid){//1.自定义判断是否可以删除，//2.可以删去执行删除操作，this.sureDelete(id,pid)},//删除分类，删除后回到上一级async sureDelete(id,pid){//1.准备删除的接口使用数据//2.发起请求，请求成功后执行下面代码this.setClassCofig(false,'', '', '')let refresh = {flag: true,cid: pid}this.$emit('refreshClass',refresh)},}};
</script>

使用tree组件

html

 <PersonalTree :activeId="currentClassfiyId" :classifyData="classifyData"@selectId="changeSelectId" @selectaddId="setAddId" @refreshClass="refreshClass"/>

<script>
// 在此处引入tree组件命名为customTreeexport default{components:{customTree},data(){return{currentClassfiyId:'',addClassifyId:[],classifyData:[], }},mounted(){this.getClassList(true) },methods:{async getClassList(flagScene,cid){// console.log(flagScene,cid)// 发送请求，获取全部分类this.classifyData = res.data.data.classify this.currentClassfiyId = cid || this.classifyData?.[0].idif(flagScene){ // 可以去获取内容} }},refreshClass({flag,cid}){// 去刷新分类列表this.getClassList(flag,cid)},setAddId(val){this.addClassifyId = val},changeSelectId(id){this.currentClassfiyId = id// 可以去获取内容},}}
</script>

classifyData的数据：

[{"id": 1033,"name": "一级分类","parent_id": 0, "level": 1,"child": [{"id": 1036,"name": "aaaaaaaaa","parent_id": 1033, "level": 2,"child": [],"is_edit_sort": true,"is_add_classify": true,"is_add_scene": true},{"id": 1035,"name": "aaaaa","parent_id": 1033,  "level": 2,"child": [{"id": 1037,"name": "a-1","parent_id": 1035, "level": 3,"child": [{"id": 1040,"name": "a-1-3","parent_id": 1037, "level": 4,"child": [],"is_edit_sort": true,"is_add_classify": false,"is_add_scene": true},{"id": 1038,"name": "a-1-1","parent_id": 1037, "level": 4,"child": [],"is_edit_sort": true,"is_add_classify": false,"is_add_scene": true}],"is_edit_sort": true,"is_add_classify": true,"is_add_scene": true}],"is_edit_sort": true,"is_add_classify": true,"is_add_scene": true}],"is_edit_sort": true,"is_add_classify": true,"is_add_scene": true
},{"id": 1032,"name": "测试分类b","parent_id": 0, "level": 1,"child": [],"is_edit_sort": true,"is_add_classify": true,"is_add_scene": true
},{"id": 1015,"name": "无操作区","parent_id": 0,"level": 1,"child": [],"is_edit_sort": false,"is_add_classify": false,"is_add_scene": false
}]

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