el-tree限制选中个数的实例

 <el-tree
          style="max-width: 600px"
          :data="Treedata"
          :check-strictly="true"
          show-checkbox
          node-key="id"
          :props="defaultProps"
          :default-expanded-keys="['1', '2']"
          ref="treeRef"
          @check="handleCheckChange"
        />

const handleCheckChange = (data: any, checked: any) => {
  const selectedNodes = treeRef.value.getCheckedNodes();
  if (selectedNodes.length > 3 && checked) {
    treeRef.value.setChecked(data, false); // 取消选中超出限制的节点
    ElMessage.warning(`您最多只能选择 ${3} 个节点！`);
  }
};

const handleCheckChange= (currNode: any, checkedInfo: any) => {
  let checkedKeys = checkedInfo.checkedKeys || [];
  let treeNodesMap = treeRef.value.store?.nodesMap || {};
  let status = checkedKeys.length >= 3;
  if (status) {
    ElMessage.warning(`您最多只能选择 ${3} 个节点！`);
  }
  Object.keys(treeNodesMap).forEach((key) => {
    let item = treeNodesMap[key] || {};
    if (!checkedKeys.includes(key)) {
      let data = item.data || {};
      data.disabled = status;
      treeRef.value.setCurrentNode(data);
    }
  });
};