html部分

 <div class="img-preview" v-for="(img,i) of list" :key="img.imageKey" v-on:mouseenter="changeActive(i+1)" v-on:mouseleave="removeActive(i+1)" :id="i+1"> //这样就给循环出来的div添加了不同的id

        	<div class="mask"></div>

            <i class="el-icon-delete" @click.prevent="delImg(i)" style="display: none;"></i>

            <img class="imgstyle"

                    :src="img.imageUrl || img.thumbUrl"

                    alt=""

                    @click="openNewImg(img.imageUrl || img.url)"

            />

        </div>

js部分

changeActive(index){

        		console.log($('#'+index ));

        		$('#'+index ).find('.el-icon-delete').show();

        	},

        	removeActive(index){

        		$('#'+index ).find('.el-icon-delete').hide();

        	},