話不多說，直接上代碼，創(chuàng)建，聲明，監(jiān)聽，

<el-menu
      class="dash-menu"
      unique-opened
      background-color="red"
      text-color="white"
      active-text-color="white"
      :default-active="navselected"
      :active="navselected"
      router
      @open="handleOpen"
      @close="handleClose"
    >

data(){
    return{
      navselected: this.$store.state.selectMenuIndex,
    }
  },
watch: {
    // 監(jiān)測store.state
    '$store.state.selectMenuIndex':'getNavType'
  },
methods: {
    getNavType(){
      this.navselected=this.$store.state.selectMenuIndex;
      if (this.navselected == "2-1") {
       this.$router.push({ path: "/home-cake" });
      }else if(this.navselected == "2-2") {
      }else if(this.navselected == "3") {
      }
    },
}

緩存部分
state.js

var vstate = {
    selectMenuIndex: "1",//默認選中頁面index
}
export default vstate

getters.js

const vgetters = {
    getSelectMenuIndex:state => state.selectMenuIndex,
}
export default vgetters

其他頁面點擊按鈕操作

clickAction(){
      this.$store.state.selectMenuIndex = "2-1";
    },