elementUI el-tree 树节点自定义图标

 <el-tree
          node-key="id"
          default-expand-all
          icon-class
          :data="treeData"
          :props="treeProps"
          @node-click="handleTreeNodeClick"
        >
          <span slot-scope="{ node, data }">
            <img v-if="data.img" width="20" height="20" :src="data.iconSrc" />
            {{ node.label }}
          </span>
 </el-tree>

src: url或者静态资源地址