swiper echarts 点击tab切换swiper解决第一

第一张不显示的问题在于 swiper 的loop属性如果true则下标打印到navList.length+1张 
最简单的方法是loop:false;

版本:
"swiper": "3.4.1",
"vue-awesome-swiper": "^3.1.3",
加载tab

  <ul class="nav">
            <li
              v-for="(item, index) in navList"
              :key="index"
              class="itemNav"
              :class="{ active: index == activeIndex }"
              @click="menuShow(index)"
            >
              {{ item }}
            </li>
          </ul>

·

  <div class="swiper_box">
            <swiper
              ref="mySwiper"
              :options="swiperOption"
              v-if="navList.length > 1"
            >
              <swiper-slide
                class="swiper-wrapper"
                v-for="(item, index) in navList"
                :key="index"
              >
             <!--    <div v-if="index == 0" class="navswiper">
                  <swiper-one
                    :Dian1="DianList"
                    v-if="DianList.length > 0"
                  ></swiper-one>
                </div>  -->
                  ···
 </swiper-slide>
 </swiper>

import { swiper, swiperSlide } from "vue-awesome-swiper";
import "swiper/dist/css/swiper.css";
export default {
  data() {
    return {
      navList: [
        // 各楼宇电，各楼宇水，自来水用量，天然气，蒸汽，餐厅流量
        "1",
        "2",
        "3",
        "4",
        "5",
        "6"
      ],
      
      activeIndex: 0,
      // 轮播图
      swiperOption: {
        observeParents: true,
        pagination: ".swiper-pagination",
        paginationClickable: true, //分页可点击
        slidesPerView: 1, //每次滑动图片一张
        slidesPerGroup: 1, //每个div只有一张图片
        loop: false, //false 不循环    true循环
        // grabCursor: true, //鼠标光标
        fadeEffect: {
          crossFade: true
        },
        autoplay: {
          delay: 2000, //秒
          stopOnLastSlide: false,
          disableOnInteraction: false //滑动不会失效
        }
      },
},
 components: {
   swiper,
    swiperSlide
  },
  computed: {
    swiper() {
      return this.$refs.mySwiper.swiper;
    }
  },
  mounted() {
    let _this = this; //轮播

    this.swiper.on("slideChangeTransitionStart", function() {
      if (this.activeIndex == _this.navList.length + 1) {
        _this.activeIndex = 1;
      } else {
        _this.activeIndex = this.activeIndex;
      }
    });
  },
 methods: {
    menuShow(index) {
      console.log("click", index);
      this.swiper.slideTo(index);
    },}