el-table树形数据 默认样式

有下级没展开是▸ 有下级展开了是▾ 没有下级的前面什么符号也没有。

更改成自定义样式

因为是vue的 <style scoped>内写CSS 样式，所以需要添加 /deep/ 进行穿透

.el-tree /deep/ .el-tree-node__expand-icon.expanded
{
    -webkit-transform: rotate(0deg);
    transform: rotate(0deg);
}
//有子节点 且未展开
.el-table/deep/ .el-icon-arrow-right:before {
  background: url('./images/folder.png') no-repeat 0 3px;
  content: '';
  display: block;
  width: 16px;
  height: 16px;
  font-size: 16px;
  background-size: 16px;
}
//有子节点 且已展开
.el-table/deep/ .el-table__expand-icon--expanded {
  .el-icon-arrow-right:before {
    background: url('./images/folderOpen2.png') no-repeat 0 3px;
    content: '';
    display: block;
    width: 15px;
    height: 20px;
    font-size: 18px;
    background-size: 21px;
  }
}
//没有子节点
.el-tree /deep/.el-tree-node__expand-icon.is-leaf::before
.el-table/deep/.el-table__placeholder::before {
  background: url('./images/file.png') no-repeat 0 3px;
  content: '';
  display: block;
  width: 16px;
  height: 18px;
  font-size: 16px;
  background-size: 16px;
}

点击打开子节点时小图标会旋转，没找到怎么解决，使用了一张左旋90°的图片

图片来自 Iconfont-阿里巴巴矢量图标库