手把手教学~基于element封装tree树状下拉框
1.组件调用代码
<template>
<div id="app">
<h1>{{`基于Element-UI组件改造的树形选择器`}}:</h1>
<!-- 调用树形下拉框组件 -->
<!-- 下拉树 -->
<selectbutton
:props="props"
:options="optionData"
:value="valueId"
:clearable="isClearable"
:accordion="isAccordion"
@getValue="getValue($event)"
height="200"
></selectbutton>
ID为：{{valueId}}
</div>
</template>
复制代码调用组件的数据
<script>
import SelectTree from "./components/treeSelect.vue";
export default {
name: "app",
components: {
SelectTree
},
data() {
return {
isClearable: true, // 可清空（可选）
isAccordion: true, // 可收起（可选）
valueId: 1, // 初始ID（可选）
props: {
// 配置项（必选）
value: "id",
label: "name",
children: "children"
// disabled:true
},
// 选项列表（必选）
list: [
{ id: 1, parentId: 0, name: "一级菜单A", rank: 1 },
{ id: 2, parentId: 0, name: "一级菜单B", rank: 1 },
{ id: 3, parentId: 0, name: "一级菜单C", rank: 1 },
{ id: 4, parentId: 1, name: "二级菜单A-A", rank: 2 },
{ id: 5, parentId: 1, name: "二级菜单A-B", rank: 2 },
{ id: 6, parentId: 2, name: "二级菜单B-A", rank: 2 },
{ id: 7, parentId: 4, name: "三级菜单A-A-A", rank: 3 },
{ id: 8, parentId: 7, name: "四级菜单A-A-A-A", rank: 4 },
{ id: 9, parentId: 0, name: "一级菜单C", rank: 1 },
{ id: 10, parentId: 0, name: "一级菜单end", rank: 1 }
],
};
},
computed: {
/* 转树形数据 */
optionData() {
let cloneData = JSON.parse(JSON.stringify(this.list)); // 对源数据深度克隆
return cloneData.filter(father => {
// 循环所有项，并添加children属性
let branchArr = cloneData.filter(child => father.id == child.parentId); // 返回每一项的子级数组
branchArr.length > 0 ? (father.children = branchArr) : ""; //给父级添加一个children属性，并赋值
return father.parentId == 0; //返回第一层
});
}
},
methods: {
// 取值
getValue(value) {
this.valueId = value;
console.log(this.valueId);
}
}
};
</script>
复制代码2.组件封装
<template>
<el-select :value="valueTitle" :clearable="clearable" @clear="clearHandle" ref="treeSelect">
<el-input
class="selectInput"
:placeholder="placeholder"
v-model="filterText">
</el-input>
<el-option :value="valueTitle" :label="valueTitle" class="options">
<el-tree id="tree-option"
ref="selectTree"
:accordion="accordion"
:data="options"
:props="props"
:node-key="props.value"
:default-expanded-keys="defaultExpandedKey"
:filter-node-method="filterNode"
@node-click="handleNodeClick">
</el-tree>
</el-option>
</el-select>
</template>
复制代码<script>
export default {
name: "el-tree-select",
props:{
/* 配置项 */
props:{
type: Object,
default:()=>{
return {
value:'id', // ID字段名
label: 'title', // 显示名称
children: 'children' // 子级字段名
}
}
},
/* 选项列表数据(树形结构的对象数组) */
options:{
type: Array,
default: ()=>{ return [] }
},
/* 初始值 */
value:{
type: Number,
default: ()=>{ return null }
},
/* 可清空选项 */
clearable:{
type:Boolean,
default:()=>{ return true }
},
/* 自动收起 */
accordion:{
type:Boolean,
default:()=>{ return false }
},
placeholder:{
type:String,
default:()=>{return "检索关键字"}
}
},
data() {
return {
filterText: '',
valueId:this.value, // 初始值
valueTitle:'',
defaultExpandedKey:[]
}
},
mounted(){
this.initHandle()
},
methods: {
// 初始化值
initHandle(){
if(this.valueId){
this.valueTitle = this.$refs.selectTree.getNode(this.valueId).data[this.props.label] // 初始化显示
this.$refs.selectTree.setCurrentKey(this.valueId) // 设置默认选中
this.defaultExpandedKey = [this.valueId] // 设置默认展开
}
this.initScroll()
},
// 初始化滚动条
initScroll(){
this.$nextTick(()=>{
let scrollWrap = document.querySelectorAll('.el-scrollbar .el-select-dropdown__wrap')[0]
let scrollBar = document.querySelectorAll('.el-scrollbar .el-scrollbar__bar')
scrollWrap.style.cssText = 'margin: 0px; max-height: none; overflow: hidden;'
scrollBar.forEach(ele => ele.style.width = 0)
})
},
// 切换选项
handleNodeClick(node){
this.valueTitle = node[this.props.label]
this.valueId = node[this.props.value]
this.$emit('getValue',this.valueId)
this.defaultExpandedKey = []
if(!node.children || !node.children.length) { //补录选择完选项弹框不能收起
this.$refs.treeSelect.blur()
}
},
// 清除选中
clearHandle(){
this.valueTitle = ''
this.valueId = null
this.defaultExpandedKey = []
this.clearSelected()
this.$emit('getValue',null)
},
/* 清空选中样式 */
clearSelected(){
let allNode = document.querySelectorAll('#tree-option .el-tree-node')
allNode.forEach((element)=>element.classList.remove('is-current'))
},
filterNode(value, data) {
if (!value) return true;
return data.name.indexOf(value) !== -1;
}
},
watch: {
value(){
this.valueId = this.value
this.initHandle()
},
filterText(val) {
this.$refs.selectTree.filter(val);
}
},
};
</script>
复制代码3.样式修改
<!-- Add "scoped" attribute to limit CSS to this component only -->
<style scoped>
.el-scrollbar .el-scrollbar__view .el-select-dropdown__item{
height: auto;
max-height: 274px;
padding: 0;
overflow: hidden;
overflow-y: auto;
}
.el-select-dropdown__item.selected{
font-weight: normal;
}
ul li >>>.el-tree .el-tree-node__content{
height:auto;
padding: 0 20px;
}
.el-tree-node__label{
font-weight: normal;
}
.el-tree >>>.is-current .el-tree-node__label{
color: #409EFF;
font-weight: 700;
}
.el-tree >>>.is-current .el-tree-node__children .el-tree-node__label{
color:#606266;
font-weight: normal;
}
.selectInput{
padding: 0 5px;
box-sizing: border-box;
}
</style>
