Ant design Tree defaultExpandAll doesnt work with button click for react

问题

Iam using Ant Design for React Js UI. Am using Tree component to show up in the list. I also have 2 button to expand and collapse the Tree list. I use the defaultExpandAll prop to manage this. On the expand and collapse button click i set a bool to true and false respectively. Button it doesn't expand on the button click. If I set True initially to that flag state it works. Is there any work Around.

I have 2 components. (Expand and collapse button are in parent component)

**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 is obtained from Redux api call.

Is there any work around.

回答1:

The states in Ant design which are prefixed with default only work when they are rendered for the first time (and hence the default).

For working out programmatic expand and collapse, you need to control the expansion of tree using expandedKeys and onExpand props.

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>
    );
  }
}

Codesandbox

回答2:

class Demo extends React.Component {
  state = {
    expandedKeys: ["0-0-0", "0-0-1"],
    autoExpandParent: true,
    selectedKeys: []
  };

  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,
      autoExpandParent: false
    });
  };

  onSelect = (selectedKeys, info) => {
    console.log("onSelect", info);
    this.setState({ selectedKeys });
  };

  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} />;
    });
  onExpandAll = () => {
    const expandedKeys = [];
    const expandMethod = arr => {
      arr.forEach(data => {
        expandedKeys.push(data.key);
        if (data.children) {
          expandMethod(data.children);
        }
      });
    };
    expandMethod(treeData);
    this.setState({ expandedKeys });
  };
  onCollapseAll = () => {
    this.setState({ expandedKeys: [] });
  };
  render() {
    return (
      <Fragment>
        <Button onClick={this.onExpandAll} type="primary">
          ExpandAll
        </Button>
        <Button onClick={this.onCollapseAll} type="primary">
          CollapseAll
        </Button>
        <Tree
          onExpand={this.onExpand}
          expandedKeys={this.state.expandedKeys}
          autoExpandParent={this.state.autoExpandParent}
          selectedKeys={this.state.selectedKeys}
        >
          {this.renderTreeNodes(treeData)}
        </Tree>
      </Fragment>
    );
  }
}

please refer to the Codesandbox link

来源：https://stackoverflow.com/questions/59891806/ant-design-tree-defaultexpandall-doesnt-work-with-button-click-for-react