动态加载单选

 <div class="zhanghu_top_zh">
              <el-form-item label="现场人员" prop="personScene">
                <!-- <el-cascader :props="props" :show-all-levels="false" v-model="formData.personScene" style="width: 100%"> </el-cascader> -->
                <el-cascader :props="props" :show-all-levels="false" v-model="personScene" style="width: 100%" @change="handCascaderChange"> </el-cascader>
              </el-form-item>
  </div>


props: {
        lazy: true,
        lazyLoad: this.lazyLoad,
        multiple: true,
      },

// 1
    lazyLoad(node, resolve) {
      this.getData(node, resolve);
    },
    // 2
    async getData(node, resolve) {
      let level = node.level;
      if (!node.data) {
        await getOrgTree({ type: 'user' }).then((res) => {
          //接口
          const nodes = Array.from(res.data).map((item) => ({
            value: item.id,
            label: item.nickName ? item.nickName : item.name,
            leaf: level >= 1,
          }));
          // // 通过调用resolve将子节点数据返回，通知组件数据加载完成
          resolve(nodes);
        });
      } else {
        await getOrgTree({ parentId: node.data.value, type: 'user' }).then((res) => {
          const nodes = Array.from(res.data).map((item) => ({
            value: item.id,
            label: item.nickName ? item.nickName : item.name,
            leaf: item.nickName ? level : level >= 4,
          }));
          // 通过调用resolve将子节点数据返回，通知组件数据加载完成
          resolve(nodes);
        });
      }
    },