Ant design Tree defaultExpandAll 不适用于单击按钮进行反应

Question

我正在使用 Ant Design for React Js UI。我使用树组件显示在列表中。我还有 2 个按钮来展开和折叠树列表。我使用defaultExpandAll属性来管理它。在展开和折叠按钮上单击我分别将布尔值设置为 true 和 false。按钮在单击按钮时不会展开。如果我最初将 True 设置为该标志状态，它就会起作用。有什么解决办法吗？

我有 2 个组件。（展开和折叠按钮位于父组件中）

**Parent Component**

    setExpandOrCollapse(value) {
        this.setState({ expandOrCollapse: value });
      }

    <HeaderRow>
                  <Button onClick={() => this.setExpandOrCollapse(true)}>Expand All</Button>
                  <Button onClick={() => this.setExpandOrCollapse(false)}>Collapse All</Button>
                </HeaderRow>

    <Card>
                  {ItemTree && (ItemTree.length > 0) ? (
                    <ItemTree
                      dataSource={ItemTree}
                      expandOrCollapse={expandOrCollapse}
                    />
                  ) : null }
                </Card>

**Child Component**
<Tree
      draggable={isDraggable}
      defaultExpandAll={expandOrCollapse}
    >
      {loopitemNodes(dataSource)}
    </Tree>

dataSource是从Redux api调用中获取的。

有什么解决办法吗？

Answer 1

Ant 设计中带有前缀的状态default仅在第一次渲染时才起作用（因此是default）。

为了实现程序化的展开和折叠，您需要控制树的使用expandedKeys和onExpand道具的展开。

import { flattenDeep } from "lodash";

class Demo extends React.Component {
  state = {
    expandedKeys: []
  };

  constructor(props) {
    super(props);
    this.keys = this.getAllKeys(treeData);
  }

  getAllKeys = data => {
    // This function makes an array of keys, this is specific for this example, you would have to adopt for your case. If your list is dynamic, also make sure that you call this function everytime data changes.
    const nestedKeys = data.map(node => {
      let childKeys = [];
      if (node.children) {
        childKeys = this.getAllKeys(node.children);
      }
      return [childKeys, node.key];
    });
    return flattenDeep(nestedKeys);
  };

  onExpand = expandedKeys => {
    console.log("onExpand", expandedKeys);
    // if not set autoExpandParent to false, if children expanded, parent can not collapse.
    // or, you can remove all expanded children keys.
    this.setState({
      expandedKeys
    });
  };

  renderTreeNodes = data =>
    data.map(item => {
      if (item.children) {
        return (
          <TreeNode title={item.title} key={item.key} dataRef={item}>
            {this.renderTreeNodes(item.children)}
          </TreeNode>
        );
      }
      return <TreeNode key={item.key} {...item} />;
    });

  expandAll = () => {
    this.setState({
      expandedKeys: this.keys
    });
  };

  collapseAll = () => {
    this.setState({
      expandedKeys: []
    });
  };

  render() {
    return (
      <Fragment>
        <button onClick={this.expandAll}>Expand All</button>
        <button onClick={this.collapseAll}>Collapse All</button>
        <Tree onExpand={this.onExpand} expandedKeys={this.state.expandedKeys}>
          {this.renderTreeNodes(treeData)}
        </Tree>
      </Fragment>
    );
  }
}

代码沙箱