原理：每一个多选框都是一个节点，每个节点就是一个wTree组件，有父级（顶级level为0）,有子级（底层list[]是空的），组件之间状态传递是通过组件通信传递，对于外部数据checkList数组的修改是通过store实现的。初始化从底层状态传递到上层，一层一层传递。改变状态，不同状态改变，修改checklist数组。大概就这个思路，下面是代码：
<template> <div> <div > <span v-for="o in levelNum"> </span> <i v-if="item.list" :class="open ? openClass : closeClass" @click="showSub"></i> <span v-else> </span> <span> <a @click="changeState"> <img src="https://www.jb51.net/assets/selectedAll.png" v-if="selectedState === 'all'"/> <img src="https://www.jb51.net/assets/selectedSub.png" v-if="selectedState === 'sub'"/> <img src="https://www.jb51.net/assets/selectedNull.png" v-if="selectedState === 'null'"/> </a> </span> <span>{{item.name}}</span> </div> <component v-show="open" :is="node" :item="o" :state="stateSub" v-for="o of item.list" :key="o.key" :level="levelNum" v-on:changeToPar="changeBySub"> </component> </div> </template> <script> export default { name: 'wTree', props: ['item', 'level', 'state'], data () { return { open: true, node: 'wTree', // 控制菜单开关的 selected: false, // 选中的情况下 selectedState: 'null', // 子组件被选中的情况下向上传递all/sub/null originInfo: 'create', // 组件信息源，create/parent/children/this openClass: 'el-icon-caret-bottom', closeClass: 'el-icon-caret-right', selectClass: 'el-icon-check', selectBg: '#1c8de0', list: [], createSwitch: true } }, computed: { levelNum () { return (this.level + 1) }, stateSub () { return { selected: this.selected, originInfo: this.originInfo } } }, methods: { showSub () { this.open = !this.open }, changeState () { if (this.selected) { this.selected = false this.selectedState = 'null' this.originInfo = 'this' for (let o of this.list) { o.selectedState = 'null' } } else { this.selected = true this.selectedState = 'all' this.originInfo = 'this' for (let o of this.list) { o.selectedState = 'all' } } let data = { id: this.item.menuId, selectedState: this.selectedState, originInfo: 'parent' } this.$emit('changeToPar', data) }, changeBySub (data) { // 如果是父组件true,判断状态，未被选中，添加id到list，selectSub=true,通知父组件，添加store的数组中，选中通知父组件，this.list.length=this.length状态改为selected // 修改自身状态，添加list let temp = data if (data.originInfo === 'create') { this.list.push(data) } else { this.originInfo = 'parent' let stateNull = 'null' let stateAll = 'all' let stateSub = 'sub' for (let o of this.list) { if (o.id === temp.id) { o.selectedState = temp.selectedState } if (o.selectedState !== 'all') { stateAll = null } if (o.selectedState !== 'null') { stateNull = null } } if (stateNull) { this.selectedState = stateNull this.selected = false } else if (stateAll) { this.selectedState = stateAll this.selected = true } else { this.selectedState = stateSub this.selected = true } let data = { id: this.item.menuId, selectedState: this.selectedState, originInfo: 'parent' } this.$emit('changeToPar', data) } } }, watch: { selected () { // 初始化 if (this.originInfo === 'create') { // 不改变值 } else { // 改变值******** if (this.selected) { // 添加值 this.$store.commit('PUSH_CHECK_LIST', this.item.menuId) } else { // 删除值 this.$store.commit('SPLICE_CHECK_LIST', this.item.menuId) } } }, state () { // 子组件得到通知，如果状态一直，不去改变，如果状态不一致改变 if (this.state.originInfo === 'this') { this.originInfo = 'this' } if (this.originInfo === 'create') { this.originInfo = 'children' } else { if (this.state.originInfo !== 'parent') { if (this.state.selected) { this.selected = true this.selectedState = 'all' if (this.list !== []) { for (let o of this.list) { o.selectedState = 'all' } } } else { this.selected = false this.selectedState = 'null' if (this.list !== []) { for (let o of this.list) { o.selectedState = 'null' } } } } } }, list () { // 初始化数组 if (this.list.length === this.item.list.length) { let stateNull = 'null' let stateAll = 'all' let stateSub = 'sub' for (let o of this.list) { if (o.selectedState !== 'all') { stateAll = null } if (o.selectedState !== 'null') { stateNull = null } } if (stateNull) { this.selectedState = stateNull this.selected = false } else if (stateAll) { this.selectedState = stateAll this.selected = true } else { this.selectedState = stateSub this.selected = true } let data = { id: this.item.menuId, selectedState: this.selectedState, originInfo: 'create' } this.$emit('changeToPar', data) } } }, created () { // 初始化，把每个组件，从最底层添加到节点列表中，这样每个子组件都在list中了，就是originInfo=create的情况下添加数组，就不用判断数组长度，直接改变状态 if (this.createSwitch) { let i = this.$store.state.checkList.indexOf(this.item.menuId) console.log(!this.item.list) console.log('-----------------------初始化') if (!this.item.list) { if (i > -1) { this.selectedState = 'all' this.selected = true } else { this.selectedState = 'null' this.selected = false } let data = { id: this.item.menuId, selectedState: this.selectedState, originInfo: 'create' } this.$emit('changeToPar', data) this.originInfo = 'this' } this.createSwitch = false } console.log(this.state) console.log('----------------created') }, updated () { console.log('-------updated=======') let i = this.$store.state.checkList.indexOf(this.item.menuId) console.log(!this.item.list) console.log('-----------------------初始化') if (!this.item.list) { if (i > -1) { this.selectedState = 'all' this.selected = true } else { this.selectedState = 'null' this.selected = false } let data = { id: this.item.menuId, selectedState: this.selectedState, originInfo: 'parent' } this.$emit('changeToPar', data) this.originInfo = 'this' } }, mounted () { console.log('=========mounted-----') } } </script>
调用 orgList带有层级的json数组
<w-tree v-for="o of orgList" :item="o" :level="0" :key="o.key"></w-tree>
总结