鼠标滑过图片背景透明黑遮罩样式

.user-info-head {
  position: relative;
  display: inline-block;
  width:150px;
  height: 200px;
  overflow: hidden;
  border: 4px solid white;
  img{
    width: 150px;
    height: 200px;
    border: 0;
    overflow: hidden;
  }
}

.user-info-head:hover:after {
  content: '+';
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  bottom: 0;
  color: #eee;
  background: rgba(0, 0, 0, 0.5);
  font-size: 44px;
  font-style: normal;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  cursor: pointer;
  line-height: 200px;
  text-align: center;
  overflow: hidden;
  // border-radius: 50%;
}

 <div class="user-info-head><img v-bind:src="options.img" title="点击上传头像" /></div>