增加节点层级，并且下面显示的数据后面有删除按钮

可以在上面的示例代码基础上进行修改，增加节点层级和删除按钮的功能。

以下是示例代码：

import React, { useState } from 'react';
import { Tree, Checkbox, List, Button } from 'antd';

const treeData = [
  {
    title: 'Node 1',
    key: '1',
    children: [
      {
        title: 'Node 1-1',
        key: '1-1',
        children: [
          {
            title: 'Node 1-1-1',
            key: '1-1-1',
          },
          {
            title: 'Node 1-1-2',
            key: '1-1-2',
          },
        ],
      },
      {
        title: 'Node 1-2',
        key: '1-2',
        children: [
          {
            title: 'Node 1-2-1',
            key: '1-2-1',
          },
          {
            title: 'Node 1-2-2',
            key: '1-2-2',
          },
        ],
      },
    ],
  },
  {
    title: 'Node 2',
    key: '2',
  },
];

function TreeDemo() {
  const [checkedKeys, setCheckedKeys] = useState([]);
  const [treeData, setTreeData] = useState(treeData);

  const onCheck = (checkedKeys) => {
    setCheckedKeys(checkedKeys);
  };

  const onAdd = (selectedKey) => {
    const newNode = {
      title: `New Node ${Math.random().toString(36).substr(2, 5)}`,
      key: `${selectedKey}-${Math.random().toString(36).substr(2, 5)}`,
      children: [],
    };

    const traverseTree = (node) => {
      if (node.key === selectedKey) {
        node.children.push(newNode);
      } else if (node.children) {
        node.children.forEach((child) => {
          traverseTree(child);
        });
      }
    };

    treeData.forEach((node) => {
      traverseTree(node);
    });

    setTreeData([...treeData]);
  };

  const onDelete = (selectedKey) => {
    const traverseTree = (node, parentNode) => {
      if (node.key === selectedKey) {
        if (parentNode) {
          parentNode.children = parentNode.children.filter(
            (child) => child.key !== selectedKey
          );
        } else {
          setTreeData(treeData.filter((node) => node.key !== selectedKey));
        }
      } else if (node.children) {
        node.children.forEach((child) => {
          traverseTree(child, node);
        });
      }
    };

    treeData.forEach((node) => {
      traverseTree(node, null);
    });

    setCheckedKeys(checkedKeys.filter((key) => key !== selectedKey));
  };

  const renderTreeNode = (node) => {
    const title = (
      <div>
        <span>{node.title}</span>
        <Button
          type="text"
          size="small"
          danger
          onClick={() => onDelete(node.key)}
        >
          Delete
        </Button>
        <Button type="text" size="small" onClick={() => onAdd(node.key)}>
          Add Child
        </Button>
      </div>
    );

    if (node.children) {
      return (
        <Tree.TreeNode title={title} key={node.key}>
          {node.children.map((child) => renderTreeNode(child))}
        </Tree.TreeNode>
      );
    } else {
      return <Tree.TreeNode title={title} key={node.key} />;
    }
  };

  const renderCheckedList = () => {
    const checkedNodes = [];

    const traverseTree = (node) => {
      if (checkedKeys.includes(node.key)) {
        checkedNodes.push(node.title);
      }

      if (node.children) {
        node.children.forEach((child) => {
          traverseTree(child);
        });
      }
    };

    treeData.forEach((node) => {
      traverseTree(node);
    });

    return (
      <List
        header={<div>Checked Nodes</div>}
        bordered
        dataSource={checkedNodes}
        renderItem={(item) => <List.Item>{item}</List.Item>}
      />
    );
  };

  return (
    <div>
      <Tree checkable checkedKeys={checkedKeys} onCheck={onCheck}>
        {treeData.map((node) => renderTreeNode(node))}
      </Tree>

      {renderCheckedList()}
    </div>
  );
}

export default TreeDemo;

首先在`treeData`中为每个节点添加一个`children`属性，来表示子节点，然后在`renderTreeNode`方法中增加删除按钮和添加子节点按钮，并且分别绑定`onDelete`和`onAdd`方法。

`onDelete`方法用来删除节点，需要遍历整个树形数据，找到要删除的节点，并且将其从父节点的`children`数组中移除。

`onAdd`方法用来添加子节点，需要在当前节点下添加一个新节点，并且更新树形数据。

最后在`Tree`组件中使用`renderTreeNode`方法来渲染树形结构，并且使用`checkedKeys`属性来绑定勾选状态，使用`onCheck`事件来监听勾选状态的变化。

同时，通过`renderCheckedList`方法来渲染勾选的节点列表，遍历整个树形数据，将勾选的节点的标题存储到`checkedNodes`数组中，最后使用`List`组件将列表展示出来。