uniapp realizes the big picture preview of the carousel

1. Bind the click event to the carousel
2. Pass the carousel index to the custom event

    <!-- 轮播图 -->
    <swiper :indicator-dots="true" :autoplay="true" :interval="3000" :duration="1000" circular="true">
      <swiper-item v-for="(item, index) in goodsInfo.pics" :key="item.pics_id">
        <image :src="item.pics_big" @click="preview(index)"></image>
      </swiper-item>
    </swiper>

// 大图预览
    preview(index) {
    
    
      // 调用uni.previewImage()方法,传递index
      uni.previewImage({
    
    
        current: index,
        // 返回所有图片的url地址数组
        urls: this.goodsInfo.pics.map((item) => item.pics_big)
      });
    }