监听图片切换事件

src/views/ebiz/goodStart/GoodStartScheme.vue

@@ -8,7 +8,7 @@
     <div id="pagination" class="bg-white">
       <van-pagination v-model="currentPage" :total-items="pics.length" :items-per-page="9" force-ellipses @change="onPageChange" />
     </div>
-    <van-image-preview id="preview" v-model="isPrevShow" :images="images" :start-position="startPosition" />
+    <van-image-preview id="preview" v-model="isPrevShow" :images="images" :start-position="startPosition" @change="prevChange" />
     <van-button class="share-btn" v-show="isPrevShow" type="danger" block @click="shareImg">分享</van-button>
   </div>
 </template>
@@ -49,6 +49,9 @@ export default {
     this.interceptAppBtn()
   },
   methods: {
+    prevChange(index) {
+      this.startPosition = index
+    },
     setPrevImgs(imgArr) {
       this.images = []
       for (let pic of imgArr) {