Vue项目img标签图片加载失败/显示不成功，显示默认图片

直接上正确代码,至于别人说的@οnerrοr=“url”，这种方法，亲测~~不可用

<img class="avatar" :src="docAvatar">

.avatar {
    width: 40px;
    height: 40px;
    position: relative;
}
.avatar:after {
    content: "";
    display: inline-block;
    position: absolute;
    z-index: 2;
    top: 0;
    left: 0;
    width: 40px;
    height: 40px;
    background-image: url("./../assets/img/doctor.jpg");
    background-size: cover;
    background-color: #fff;
}