Html

  	 <el-card
        shadow="hover"
        class="solo flex-2"
        style="height: calc(100vh - 1.6rem); border: 1px solid #ebeef5"
      >
        <div slot="header" class="clearfix">
          <span>问题分类</span>
        </div>
        <div class="scroll-tree">
          <el-scrollbar style="height: 100%">
            <el-tree
              :data="data"
              :props="defaultProps"
              @node-click="handleNodeClick"
              node-key="id"
            ></el-tree>
          </el-scrollbar>
        </div>
      </el-card>

样式

/* 添加水平滚动条和纵向滚动条 */
.scroll-tree {
  overflow: auto;
  height: calc(100vh - 1.6rem - 60px);
}
.scroll-tree ::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}
.el-tree {
  display: inline-block;
  min-width: 100%;
}
/deep/.solo .el-card__body {
  padding: 0px;
}

点击节点高亮

• tree 标签添加属性 highlight-current

/deep/.el-tree--highlight-current
  .el-tree-node.is-current
  > .el-tree-node__content {
  background-color: #318eff;
  color: #fff;
}