效果如下：

html

 div id="app" 
 div 
 span v-for="item in selectedItems" {{item.name}} i v-on:click="deleteSelectedItem($index)" /i /span 
 input v-model="inputItem" type="text" v-on:focus="showDropmenu" v-on:keyup.enter="addItem" 
 /div 
 div v-show="isShowDropmenu" 
 button v-for="item in cataName" v-on:click="showCataList($index)" {{item.name}} /button 
 button v-on:click="hideDropmenu" i /i /button 
 div v-for="item in cataList" v-show="item.isShow" 
 span v-for="one in item.items" v-on:click="addByClick(one)" {{one}} /span 
 /div 
 /div 
 /div 

js

new Vue({
 el:'#app',
 data:{
 selectedItems: [{
 name: 'NodeJs'
 isShowDropmenu: false,
 inputItem:'',
 cataName:[{name:'开发语法'}, {name: '系统设备'}],
 cataList:[{
 isShow: true,
 items:['js','c++','java']
 isShow: false,
 items:['windows','chrome','linux']
 methods:{
 showDropmenu: function(event){
 console.log('showDropmenu');
 this.isShowDropmenu = true;
 hideDropmenu: function(event){
 this.isShowDropmenu = false;
 console.log('hideDropmenu');
 test: function(){
 console.log('test');
 addItem: function(){
 this.selectedItems.push({name: this.inputItem});
 this.inputItem = "";
 deleteSelectedItem: function(index){
 this.selectedItems.splice(index, 1);
 showCataList: function(index){
 var i = this.cataList.length;
 while(i--){
 i === index this.cataList[i].isShow = true: this.cataList[i].isShow = false;
 addByClick: function(name){
 var i = this.selectedItems.length;
 while(i--){
 if(this.selectedItems[i].name === name){
 return;
 this.selectedItems.push({name: name});

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持凡科。