cover-image组件中想让图片截取中间部分显示要怎么做，设置了object-fit:cover；和mode="aspectFill"都没有效果！

                
 <cover-view class="videoCoverBox" v-if="isShowPlayIcon">
    <cover-image :src="info.img" class="coverImg" mode="aspectFill"></cover-image>
    <cover-image :src="playIcon" class="playIcon" [@click](/user/click)="clickPlay"></cover-image>
 </cover-view>                   
                    
                
            
.coverImg {
    width: 686rpx;
    height: 386rpx;
    object-fit: cover;
}