原生js实现上传图片控件

<divclass="card"><inputid="upload"type="file"accept=".jpg"/><divclass="view"><!-- 上传成功后 --><divid="imgContainer"class="img-container"><imgid="img"/><!-- 鼠标移入展示 查看 与 删除 操作 --><divclass="img-mask"><spanid="showImg">查看</span><spanid="delImg">删除</span></div></div><!-- 上传成功前 --><spanid="icon">+</span></div></div>

.card {
    position: relative;
    width: 200px;
    height: 140px;
    padding: 5px;
    margin-right: 20px;
    border: 1px dashed #d9d9d9;
    border-radius: 6px;
    margin: 300px auto;
}
.card input {
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    cursor: pointer;
}
.card .view {
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
}
.card .view #icon {
    display: inline-block;
    font-size: 30px;
}
.card .view .img-container {
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    display: none;
}
.img-container img {
    width: 100%;
    height: 100%;
}
.img-container .img-mask {
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    background: rgba(0, 0, 0, .3);
    transition: all .5s ease;
    display: flex;
    justify-content: center;
    align-items: center;
}
.img-container:hover .img-mask {
    opacity: 1;
}
.img-mask span {
    color: #fff;
    margin: 0 10px;
    cursor: pointer;
}