Infra DesignTree树形控件
多层次的结构列表。
何时使用#
文件夹、组织架构、生物分类、国家地区等等，世间万物的大多数结构都是树形结构。使用 树控件 可以完整展现其中的层级关系，并具有展开收起选择等交互功能。
代码演示
最简单的用法，展示可勾选，可选中，禁用，默认展开等功能。
TypeScript
JavaScript
import { Tree } from 'infrad';
import type { DataNode, TreeProps } from 'infrad/lib/tree';
import React from 'react';
const treeData: DataNode[] = [
{
title: 'parent 1',
key: '0-0',
children: [
{
title: 'parent 1-0',
key: '0-0-0',
disabled: true,
children: [
{
title: 'leaf',
key: '0-0-0-0',
disableCheckbox: true,
},
{
title: 'leaf',
key: '0-0-0-1',
},
],
},
{
title: 'parent 1-1',
key: '0-0-1',
children: [{ title: <span style={{ color: '#2673dd' }}>sss</span>, key: '0-0-1-0' }],
},
],
},
];
const App: React.FC = () => {
const onSelect: TreeProps['onSelect'] = (selectedKeys, info) => {
console.log('selected', selectedKeys, info);
};
const onCheck: TreeProps['onCheck'] = (checkedKeys, info) => {
console.log('onCheck', checkedKeys, info);
};
return (
<Tree
checkable
defaultExpandedKeys={['0-0-0', '0-0-1']}
defaultSelectedKeys={['0-0-0', '0-0-1']}
defaultCheckedKeys={['0-0-0', '0-0-1']}
onSelect={onSelect}
onCheck={onCheck}
treeData={treeData}
/>
);
};
export default App;将节点拖拽到其他节点内部或前后。
TypeScript
JavaScript
import { Tree } from 'infrad';
import type { DataNode, TreeProps } from 'infrad/lib/tree';
import React, { useState } from 'react';
const x = 3;
const y = 2;
const z = 1;
const defaultData: DataNode[] = [];
const generateData = (_level: number, _preKey?: React.Key, _tns?: DataNode[]) => {
const preKey = _preKey || '0';
const tns = _tns || defaultData;
const children = [];
for (let i = 0; i < x; i++) {
const key = `${preKey}-${i}`;
tns.push({ title: key, key });
if (i < y) {
children.push(key);
}
}
if (_level < 0) {
return tns;
}
const level = _level - 1;
children.forEach((key, index) => {
tns[index].children = [];
return generateData(level, key, tns[index].children);
});
};
generateData(z);
const App: React.FC = () => {
const [gData, setGData] = useState(defaultData);
const [expandedKeys] = useState(['0-0', '0-0-0', '0-0-0-0']);
const onDragEnter: TreeProps['onDragEnter'] = info => {
console.log(info);
// expandedKeys 需要受控时设置
// setExpandedKeys(info.expandedKeys)
};
const onDrop: TreeProps['onDrop'] = info => {
console.log(info);
const dropKey = info.node.key;
const dragKey = info.dragNode.key;
const dropPos = info.node.pos.split('-');
const dropPosition = info.dropPosition - Number(dropPos[dropPos.length - 1]);
const loop = (
data: DataNode[],
key: React.Key,
callback: (node: DataNode, i: number, data: DataNode[]) => void,
) => {
for (let i = 0; i < data.length; i++) {
if (data[i].key === key) {
return callback(data[i], i, data);
}
if (data[i].children) {
loop(data[i].children!, key, callback);
}
}
};
const data = [...gData];
// Find dragObject
let dragObj: DataNode;
loop(data, dragKey, (item, index, arr) => {
arr.splice(index, 1);
dragObj = item;
});
if (!info.dropToGap) {
// Drop on the content
loop(data, dropKey, item => {
item.children = item.children || [];
// where to insert 示例添加到头部，可以是随意位置
item.children.unshift(dragObj);
});
} else if (
((info.node as any).props.children || []).length > 0 && // Has children
(info.node as any).props.expanded && // Is expanded
dropPosition === 1 // On the bottom gap
) {
loop(data, dropKey, item => {
item.children = item.children || [];
// where to insert 示例添加到头部，可以是随意位置
item.children.unshift(dragObj);
// in previous version, we use item.children.push(dragObj) to insert the
// item to the tail of the children
});
} else {
let ar: DataNode[] = [];
let i: number;
loop(data, dropKey, (_item, index, arr) => {
ar = arr;
i = index;
});
if (dropPosition === -1) {
ar.splice(i!, 0, dragObj!);
} else {
ar.splice(i! + 1, 0, dragObj!);
}
}
setGData(data);
};
return (
<Tree
className="draggable-tree"
defaultExpandedKeys={expandedKeys}
draggable
blockNode
onDragEnter={onDragEnter}
onDrop={onDrop}
treeData={gData}
/>
);
};
export default App;可搜索的树。
TypeScript
JavaScript
import { Input, Tree } from 'infrad';
import type { DataNode } from 'infrad/lib/tree';
import React, { useMemo, useState } from 'react';
const { Search } = Input;
const x = 3;
const y = 2;
const z = 1;
const defaultData: DataNode[] = [];
const generateData = (_level: number, _preKey?: React.Key, _tns?: DataNode[]) => {
const preKey = _preKey || '0';
const tns = _tns || defaultData;
const children = [];
for (let i = 0; i < x; i++) {
const key = `${preKey}-${i}`;
tns.push({ title: key, key });
if (i < y) {
children.push(key);
}
}
if (_level < 0) {
return tns;
}
const level = _level - 1;
children.forEach((key, index) => {
tns[index].children = [];
return generateData(level, key, tns[index].children);
});
};
generateData(z);
const dataList: { key: React.Key; title: string }[] = [];
const generateList = (data: DataNode[]) => {
for (let i = 0; i < data.length; i++) {
const node = data[i];
const { key } = node;
dataList.push({ key, title: key as string });
if (node.children) {
generateList(node.children);
}
}
};
generateList(defaultData);
const getParentKey = (key: React.Key, tree: DataNode[]): React.Key => {
let parentKey: React.Key;
for (let i = 0; i < tree.length; i++) {
const node = tree[i];
if (node.children) {
if (node.children.some(item => item.key === key)) {
parentKey = node.key;
} else if (getParentKey(key, node.children)) {
parentKey = getParentKey(key, node.children);
}
}
}
return parentKey!;
};
const App: React.FC = () => {
const [expandedKeys, setExpandedKeys] = useState<React.Key[]>([]);
const [searchValue, setSearchValue] = useState('');
const [autoExpandParent, setAutoExpandParent] = useState(true);
const onExpand = (newExpandedKeys: string[]) => {
setExpandedKeys(newExpandedKeys);
setAutoExpandParent(false);
};
const onChange = (e: React.ChangeEvent<HTMLInputElement>) => {
const { value } = e.target;
const newExpandedKeys = dataList
.map(item => {
if (item.title.indexOf(value) > -1) {
return getParentKey(item.key, defaultData);
}
return null;
})
.filter((item, i, self) => item && self.indexOf(item) === i);
setExpandedKeys(newExpandedKeys as React.Key[]);
setSearchValue(value);
setAutoExpandParent(true);
};
const treeData = useMemo(() => {
const loop = (data: DataNode[]): DataNode[] =>
data.map(item => {
const strTitle = item.title as string;
const index = strTitle.indexOf(searchValue);
const beforeStr = strTitle.substring(0, index);
const afterStr = strTitle.slice(index + searchValue.length);
const title =
index > -1 ? (
<span>
{beforeStr}
<span className="site-tree-search-value">{searchValue}</span>
{afterStr}
</span>
) : (
<span>{strTitle}</span>
);
if (item.children) {
return { title, key: item.key, children: loop(item.children) };
}
return {
title,
key: item.key,
};
});
return loop(defaultData);
}, [searchValue]);
return (
<div>
<Search style={{ marginBottom: 8 }} placeholder="Search" onChange={onChange} />
<Tree
onExpand={onExpand}
expandedKeys={expandedKeys}
autoExpandParent={autoExpandParent}
treeData={treeData}
/>
</div>
);
};
export default App;.site-tree-search-value {
color: #f50;
}parent 1
leaf
leaf
可以针对不同的节点定制图标。
TypeScript
JavaScript
import {
DownOutlined,
FrownFilled,
FrownOutlined,
MehOutlined,
SmileOutlined,
} from 'infra-design-icons';
import { Tree } from 'infrad';
import type { DataNode } from 'infrad/lib/tree';
import React from 'react';
const treeData: DataNode[] = [
{
title: 'parent 1',
key: '0-0',
icon: <SmileOutlined />,
children: [
{
title: 'leaf',
key: '0-0-0',
icon: <MehOutlined />,
},
{
title: 'leaf',
key: '0-0-1',
icon: ({ selected }) => (selected ? <FrownFilled /> : <FrownOutlined />),
},
],
},
];
const App: React.FC = () => (
<Tree
showIcon
defaultExpandAll
defaultSelectedKeys={['0-0-0']}
switcherIcon={<DownOutlined />}
treeData={treeData}
/>
);
export default App;自定义展开/折叠图标。
TypeScript
JavaScript
import { DownOutlined } from 'infra-design-icons';
import { Tree } from 'infrad';
import type { DataNode, TreeProps } from 'infrad/lib/tree';
import React from 'react';
const treeData: DataNode[] = [
{
title: 'parent 1',
key: '0-0',
children: [
{
title: 'parent 1-0',
key: '0-0-0',
children: [
{
title: 'leaf',
key: '0-0-0-0',
},
{
title: 'leaf',
key: '0-0-0-1',
},
{
title: 'leaf',
key: '0-0-0-2',
},
],
},
{
title: 'parent 1-1',
key: '0-0-1',
children: [
{
title: 'leaf',
key: '0-0-1-0',
},
],
},
{
title: 'parent 1-2',
key: '0-0-2',
children: [
{
title: 'leaf',
key: '0-0-2-0',
},
{
title: 'leaf',
key: '0-0-2-1',
},
],
},
],
},
];
const App: React.FC = () => {
const onSelect: TreeProps['onSelect'] = (selectedKeys, info) => {
console.log('selected', selectedKeys, info);
};
return (
<Tree
showLine
switcherIcon={<DownOutlined />}
defaultExpandedKeys={['0-0-0']}
onSelect={onSelect}
treeData={treeData}
/>
);
};
export default App;受控操作示例
TypeScript
JavaScript
import { Tree } from 'infrad';
import type { DataNode } from 'infrad/lib/tree';
import React, { useState } from 'react';
const treeData: DataNode[] = [
{
title: '0-0',
key: '0-0',
children: [
{
title: '0-0-0',
key: '0-0-0',
children: [
{ title: '0-0-0-0', key: '0-0-0-0' },
{ title: '0-0-0-1', key: '0-0-0-1' },
{ title: '0-0-0-2', key: '0-0-0-2' },
],
},
{
title: '0-0-1',
key: '0-0-1',
children: [
{ title: '0-0-1-0', key: '0-0-1-0' },
{ title: '0-0-1-1', key: '0-0-1-1' },
{ title: '0-0-1-2', key: '0-0-1-2' },
],
},
{
title: '0-0-2',
key: '0-0-2',
},
],
},
{
title: '0-1',
key: '0-1',
children: [
{ title: '0-1-0-0', key: '0-1-0-0' },
{ title: '0-1-0-1', key: '0-1-0-1' },
{ title: '0-1-0-2', key: '0-1-0-2' },
],
},
{
title: '0-2',
key: '0-2',
},
];
const App: React.FC = () => {
const [expandedKeys, setExpandedKeys] = useState<React.Key[]>(['0-0-0', '0-0-1']);
const [checkedKeys, setCheckedKeys] = useState<React.Key[]>(['0-0-0']);
const [selectedKeys, setSelectedKeys] = useState<React.Key[]>([]);
const [autoExpandParent, setAutoExpandParent] = useState<boolean>(true);
const onExpand = (expandedKeysValue: React.Key[]) => {
console.log('onExpand', expandedKeysValue);
// if not set autoExpandParent to false, if children expanded, parent can not collapse.
// or, you can remove all expanded children keys.
setExpandedKeys(expandedKeysValue);
setAutoExpandParent(false);
};
const onCheck = (checkedKeysValue: React.Key[]) => {
console.log('onCheck', checkedKeysValue);
setCheckedKeys(checkedKeysValue);
};
const onSelect = (selectedKeysValue: React.Key[], info: any) => {
console.log('onSelect', info);
setSelectedKeys(selectedKeysValue);
};
return (
<Tree
checkable
onExpand={onExpand}
expandedKeys={expandedKeys}
autoExpandParent={autoExpandParent}
onCheck={onCheck}
checkedKeys={checkedKeys}
onSelect={onSelect}
selectedKeys={selectedKeys}
treeData={treeData}
/>
);
};
export default App;点击展开节点，动态加载数据。
TypeScript
JavaScript
import { Tree } from 'infrad';
import React, { useState } from 'react';
interface DataNode {
title: string;
key: string;
isLeaf?: boolean;
children?: DataNode[];
}
const initTreeData: DataNode[] = [
{ title: 'Expand to load', key: '0' },
{ title: 'Expand to load', key: '1' },
{ title: 'Tree Node', key: '2', isLeaf: true },
];
// It's just a simple demo. You can use tree map to optimize update perf.
const updateTreeData = (list: DataNode[], key: React.Key, children: DataNode[]): DataNode[] =>
list.map(node => {
if (node.key === key) {
return {
...node,
children,
};
}
if (node.children) {
return {
...node,
children: updateTreeData(node.children, key, children),
};
}
return node;
});
const App: React.FC = () => {
const [treeData, setTreeData] = useState(initTreeData);
const onLoadData = ({ key, children }: any) =>
new Promise<void>(resolve => {
if (children) {
resolve();
return;
}
setTimeout(() => {
setTreeData(origin =>
updateTreeData(origin, key, [
{ title: 'Child Node', key: `${key}-0` },
{ title: 'Child Node', key: `${key}-1` },
]),
);
resolve();
}, 1000);
});
return <Tree loadData={onLoadData} treeData={treeData} />;
};
export default App;showLine:
showIcon:
showLeafIcon:
showIcon:
showLeafIcon:
节点之间带连接线的树，常用于文件目录结构展示。使用 showLine 开启，可以用 switcherIcon 修改默认图标。
TypeScript
JavaScript
import { CarryOutOutlined, FormOutlined } from 'infra-design-icons';
import { Switch, Tree } from 'infrad';
import type { DataNode } from 'infrad/lib/tree';
import React, { useState } from 'react';
const treeData: DataNode[] = [
{
title: 'parent 1',
key: '0-0',
icon: <CarryOutOutlined />,
children: [
{
title: 'parent 1-0',
key: '0-0-0',
icon: <CarryOutOutlined />,
children: [
{ title: 'leaf', key: '0-0-0-0', icon: <CarryOutOutlined /> },
{
title: (
<>
<div>multiple line title</div>
<div>multiple line title</div>
</>
),
key: '0-0-0-1',
icon: <CarryOutOutlined />,
},
{ title: 'leaf', key: '0-0-0-2', icon: <CarryOutOutlined /> },
],
},
{
title: 'parent 1-1',
key: '0-0-1',
icon: <CarryOutOutlined />,
children: [{ title: 'leaf', key: '0-0-1-0', icon: <CarryOutOutlined /> }],
},
{
title: 'parent 1-2',
key: '0-0-2',
icon: <CarryOutOutlined />,
children: [
{ title: 'leaf', key: '0-0-2-0', icon: <CarryOutOutlined /> },
{
title: 'leaf',
key: '0-0-2-1',
icon: <CarryOutOutlined />,
switcherIcon: <FormOutlined />,
},
],
},
],
},
{
title: 'parent 2',
key: '0-1',
icon: <CarryOutOutlined />,
children: [
{
title: 'parent 2-0',
key: '0-1-0',
icon: <CarryOutOutlined />,
children: [
{ title: 'leaf', key: '0-1-0-0', icon: <CarryOutOutlined /> },
{ title: 'leaf', key: '0-1-0-1', icon: <CarryOutOutlined /> },
],
},
],
},
];
const App: React.FC = () => {
const [showLine, setShowLine] = useState<boolean | { showLeafIcon: boolean }>(true);
const [showIcon, setShowIcon] = useState<boolean>(false);
const [showLeafIcon, setShowLeafIcon] = useState<boolean>(true);
const onSelect = (selectedKeys: React.Key[], info: any) => {
console.log('selected', selectedKeys, info);
};
const onSetLeafIcon = (checked: boolean) => {
setShowLeafIcon(checked);
setShowLine({ showLeafIcon: checked });
};
const onSetShowLine = (checked: boolean) => {
setShowLine(checked ? { showLeafIcon } : false);
};
return (
<div>
<div style={{ marginBottom: 16 }}>
showLine: <Switch checked={!!showLine} onChange={onSetShowLine} />
<br />
<br />
showIcon: <Switch checked={showIcon} onChange={setShowIcon} />
<br />
<br />
showLeafIcon: <Switch checked={showLeafIcon} onChange={onSetLeafIcon} />
</div>
<Tree
showLine={showLine}
showIcon={showIcon}
defaultExpandedKeys={['0-0-0']}
onSelect={onSelect}
treeData={treeData}
/>
</div>
);
};
export default App;parent 0
leaf 0-0
leaf 0-1
parent 1
leaf 1-0
leaf 1-1
内置的目录树，multiple 模式支持 ctrl(Windows) / command(Mac) 复选。
TypeScript
JavaScript
import { Tree } from 'infrad';
import type { DataNode, DirectoryTreeProps } from 'infrad/lib/tree';
import React from 'react';
const { DirectoryTree } = Tree;
const treeData: DataNode[] = [
{
title: 'parent 0',
key: '0-0',
children: [
{ title: 'leaf 0-0', key: '0-0-0', isLeaf: true },
{ title: 'leaf 0-1', key: '0-0-1', isLeaf: true },
],
},
{
title: 'parent 1',
key: '0-1',
children: [
{ title: 'leaf 1-0', key: '0-1-0', isLeaf: true },
{ title: 'leaf 1-1', key: '0-1-1', isLeaf: true },
],
},
];
const App: React.FC = () => {
const onSelect: DirectoryTreeProps['onSelect'] = (keys, info) => {
console.log('Trigger Select', keys, info);
};
const onExpand: DirectoryTreeProps['onExpand'] = (keys, info) => {
console.log('Trigger Expand', keys, info);
};
return (
<DirectoryTree
multiple
defaultExpandAll
onSelect={onSelect}
onExpand={onExpand}
treeData={treeData}
/>
);
};
export default App;使用 height 属性则切换为虚拟滚动。
TypeScript
JavaScript
import { Tree } from 'infrad';
import type { DataNode } from 'infrad/lib/tree';
import React from 'react';
const dig = (path = '0', level = 3) => {
const list = [];
for (let i = 0; i < 10; i += 1) {
const key = `${path}-${i}`;
const treeNode: DataNode = {
title: key,
key,
};
if (level > 0) {
treeNode.children = dig(key, level - 1);
}
list.push(treeNode);
}
return list;
};
const treeData = dig();
const App: React.FC = () => <Tree treeData={treeData} height={233} defaultExpandAll />;
export default App;API#
Tree props#
| 参数 | 说明 | 类型 | 默认值 | 版本 |
|---|---|---|---|---|
| allowDrop | 是否允许拖拽时放置在该节点 | ({ dropNode, dropPosition }) => boolean | - | |
| autoExpandParent | 是否自动展开父节点 | boolean | false | |
| blockNode | 是否节点占据一行 | boolean | false | |
| checkable | 节点前添加 Checkbox 复选框 | boolean | false | |
| checkedKeys | （受控）选中复选框的树节点（注意：父子节点有关联，如果传入父节点 key，则子节点自动选中；相应当子节点 key 都传入，父节点也自动选中。当设置 checkable 和 checkStrictly，它是一个有checked和halfChecked属性的对象，并且父子节点的选中与否不再关联 | string[] | {checked: string[], halfChecked: string[]} | [] | |
| checkStrictly | checkable 状态下节点选择完全受控（父子节点选中状态不再关联） | boolean | false | |
| defaultCheckedKeys | 默认选中复选框的树节点 | string[] | [] | |
| defaultExpandAll | 默认展开所有树节点 | boolean | false | |
| defaultExpandedKeys | 默认展开指定的树节点 | string[] | [] | |
| defaultExpandParent | 默认展开父节点 | boolean | true | |
| defaultSelectedKeys | 默认选中的树节点 | string[] | [] | |
| disabled | 将树禁用 | boolean | false | |
| draggable | 设置节点可拖拽，可以通过 icon: false 关闭拖拽提示图标 | boolean | ((node: DataNode) => boolean) | { icon?: React.ReactNode | false, nodeDraggable?: (node: DataNode) => boolean } | false | config: 4.17.0 |
| expandedKeys | （受控）展开指定的树节点 | string[] | [] | |
| fieldNames | 自定义节点 title、key、children 的字段 | object | { title: title, key: key, children: children } | 4.17.0 |
| filterTreeNode | 按需筛选树节点（高亮），返回 true | function(node) | - | |
| height | 设置虚拟滚动容器高度，设置后内部节点不再支持横向滚动 | number | - | |
| icon | 自定义树节点图标。 | ReactNode | (props) => ReactNode | - | |
| loadData | 异步加载数据 | function(node) | - | |
| loadedKeys | （受控）已经加载的节点，需要配合 loadData 使用 | string[] | [] | |
| multiple | 支持点选多个节点（节点本身） | boolean | false | |
| rootClassName | 添加在 Tree 最外层的 className | string | - | 4.20.0 |
| rootStyle | 添加在 Tree 最外层的 style | CSSProperties | - | 4.20.0 |
| selectable | 是否可选中 | boolean | true | |
| selectedKeys | （受控）设置选中的树节点 | string[] | - | |
| showIcon | 是否展示 TreeNode title 前的图标，没有默认样式，如设置为 true，需要自行定义图标相关样式 | boolean | false | |
| showLine | 是否展示连接线 | boolean | {showLeafIcon: boolean} | false | |
| switcherIcon | 自定义树节点的展开/折叠图标 | ReactNode | (({ expanded: boolean }) => React.ReactNode) | - | renderProps: 4.20.0 |
| titleRender | 自定义渲染节点 | (nodeData) => ReactNode | - | 4.5.0 |
| treeData | treeNodes 数据，如果设置则不需要手动构造 TreeNode 节点（key 在整个树范围内唯一） | array<{key, title, children, [disabled, selectable]}> | - | |
| virtual | 设置 false 时关闭虚拟滚动 | boolean | true | 4.1.0 |
| onCheck | 点击复选框触发 | function(checkedKeys, e:{checked: bool, checkedNodes, node, event, halfCheckedKeys}) | - | |
| onDragEnd | dragend 触发时调用 | function({event, node}) | - | |
| onDragEnter | dragenter 触发时调用 | function({event, node, expandedKeys}) | - | |
| onDragLeave | dragleave 触发时调用 | function({event, node}) | - | |
| onDragOver | dragover 触发时调用 | function({event, node}) | - | |
| onDragStart | 开始拖拽时调用 | function({event, node}) | - | |
| onDrop | drop 触发时调用 | function({event, node, dragNode, dragNodesKeys}) | - | |
| onExpand | 展开/收起节点时触发 | function(expandedKeys, {expanded: bool, node}) | - | |
| onLoad | 节点加载完毕时触发 | function(loadedKeys, {event, node}) | - | |
| onRightClick | 响应右键点击 | function({event, node}) | - | |
| onSelect | 点击树节点触发 | function(selectedKeys, e:{selected: bool, selectedNodes, node, event}) | - |
TreeNode props#
| 参数 | 说明 | 类型 | 默认值 | |
|---|---|---|---|---|
| checkable | 当树为 checkable 时，设置独立节点是否展示 Checkbox | boolean | - | |
| disableCheckbox | 禁掉 checkbox | boolean | false | |
| disabled | 禁掉响应 | boolean | false | |
| icon | 自定义图标。可接收组件，props 为当前节点 props | ReactNode | (props) => ReactNode | - | |
| isLeaf | 设置为叶子节点 (设置了 loadData 时有效)。为 false 时会强制将其作为父节点 | boolean | - | |
| key | 被树的 (default)ExpandedKeys / (default)CheckedKeys / (default)SelectedKeys 属性所用。注意：整个树范围内的所有节点的 key 值不能重复！ | string | (内部计算出的节点位置) | |
| selectable | 设置节点是否可被选中 | boolean | true | |
| title | 标题 | ReactNode | --- |
DirectoryTree props#
| 参数 | 说明 | 类型 | 默认值 |
|---|---|---|---|
| expandAction | 目录展开逻辑，可选：false | click | doubleClick | string | boolean | click |
注意#
在 3.4.0 之前：树节点可以有很多，但在设置 checkable 时，将会花费更多的计算时间，因此我们缓存了一些计算结果（this.treeNodesStates）来复用，避免多次重复计算，以此提高性能。但这也带来了一些限制，当你异步加载树节点时，你需要这样渲染树：
{
this.state.treeData.length ? (
<Tree>
{this.state.treeData.map(data => (
<TreeNode />
))}
</Tree>
) : (
'loading tree'
);
}Tree 方法#
| 名称 | 说明 |
|---|---|
| scrollTo({ key: string | number; align?: 'top' | 'bottom' | 'auto'; offset?: number }) | 虚拟滚动下，滚动到指定 key 条目 |
FAQ#
在 showLine 时，如何隐藏子节点图标？#
文件图标通过 switcherIcon 来实现，如果不需要你可以覆盖对应的样式：https://codesandbox.io/s/883vo47xp8
defaultExpandedAll 在异步加载数据时为何不生效？#
default 前缀属性只有在初始化时生效，因而异步加载数据时 defaultExpandedAll 已经执行完成。你可以通过受控 expandedKeys 或者在数据加载完成后渲染 Tree 来实现全部展开。
虚拟滚动的限制#
虚拟滚动通过在仅渲染可视区域的元素来提升渲染性能。但是同时由于不会渲染所有节点，所以无法自动拓转横向宽度（比如超长 title 的横向滚动条）。
disabled 节点在树中的关系是什么？#
Tree 通过传导方式进行数据变更。无论是展开还是勾选，它都会从变更的节点开始向上、向下传导变化，直到遍历的当前节点是 disabled 时停止。因而如果控制的节点本身为 disabled 时，那么它只会修改本身而不会影响其他节点。举例来说，一个父节点包含 3 个子节点，其中一个为 disabled 状态。那么勾选父节点，只会影响其余两个子节点变成勾选状态。勾选两个子节点后，无论 disabled 节点什么状态，父节点都会变成勾选状态。
这种传导终止的方式是为了防止通过勾选子节点使得 disabled 父节点变成勾选状态，而用户无法直接勾选 disabled 父节点更改其状态导致的交互矛盾。如果你有着自己的传导需求，可以通过 checkStrictly 自定义勾选逻辑。