<div id="app">
<div style="margin-bottom: 4px;">
  <span class="selectedItem" v-for="item in selectedItems">{{item.name}} <i class="red fa fa-close (alias)"
  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 class="red fa fa-close (alias)"></i></button>
  <div v-for="item in cataList" v-show="item.isShow">
    <span v-for="one in item.items" class="item" v-on:click="addByClick(one)">{{one}}</span>
  </div>
</div>
</div>

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});
      }
    }
  });