el-scrollbar是elementui隐藏的一个组件使用方法如下：

<el-scrollbar style="height: calc(100vh - 200px);" ref="myScrollbar">
          <p v-for="(message, index) in messages" :key="index"><span class="nick"> {{message.nick}} </span>:<br/>{{message.text}}</p>
        </el-scrollbar>

this.$nextTick(() => {
            this.$refs['myScrollbar'].wrap.scrollTop = this.$refs['myScrollbar'].wrap.scrollHeight
          })

// 必要的
//隐藏底部滚动条
/deep/ .el-scrollbar__wrap {
  overflow: scroll;
  height: 100% !important;
  overflow-x: hidden !important;
}