React JS - Material UI ListItem（带有 Collapse API）onClick 展开/折叠所有子列表项而不是选定的子列表项

Question

我正在使用 React JS - Material UI ListItem （使用 Collapse API）实现列表的展开/折叠功能

当我单击 ListItem 时，它会展开/折叠所有子列表项而不是选定的子列表项。

这是示例代码。看起来我在其中一个元素中设置了不正确的键值，但无法弄清楚。有人能帮我吗？如果信息不充分，请告诉我

贾法尔

class CategoriesResults extends Component {
  constructor(props) {
    super(props);
    this.state = {
      open: false
    };
    this.handleClick = this.handleClick.bind(this);
  }

  handleClick() {
    console.log("Handle Clicked....");
     this.setState(prevState => ({
       open: !prevState.open
     }));
  }

  render() {
    const docs = data.documents;  //this coming from a json file, please see below for the sample json
     return (
      <div>
        <List component='nav' aria-labelledby='nested-list-subheader'>
          {docs.map(doc => {
            return (
              <div key={doc.Id}>
                <ListItem button key={doc.Id} onClick={this.handleClick}>
                  <ListItemText primary={doc.Name} />
                  {this.state.open ? <ExpandLess /> : <ExpandMore />}
                </ListItem>
                <Collapse
                  key={doc.Sheets.Id}
                  in={this.state.open}
                  timeout='auto'
                  unmountOnExit
                >
                  <List component='li' disablePadding key={doc.Id}>
                    {doc.Sheets.map(sheet => {
                      return (
                        <ListItem button key={sheet.Id}>
                          <ListItemIcon>
                            <InsertDriveFileTwoToneIcon />
                          </ListItemIcon>
                          <ListItemText key={sheet.Id} primary={sheet.Title} />
                        </ListItem>
                      );
                    })}
                  </List>
                </Collapse>
                <Divider />
              </div>
            );
          })}
        </List>     
      </div>
    );
  }
}


**Sample JSON**

{
  "documents": [
    {
      "Id": 1,
      "Name": "Category 1",
      "Sheets": [
        {
          "Id": 1,
          "Title": "Title1 "
        },
        {
          "Id": 2,
          "Title": "Title 2"
        },
        {
          "Id": 3,
          "Title": "Title 3"
        }
      ]
    }
}

Answer 1

我已将其转换为一个使用钩子的基于函数的组件，以便未来的人们可以轻松理解它：

import React, { useState } from 'react'

const CustomizedListItem = ({ doc }) => {
    const [ open, setOpen ] = useState(false)
    const handleClick = () => {
        setOpen(!open)
    }
    
    return (
        <div>
            <ListItem button key={doc.Id} onClick={handleClick}>
                <ListItemText primary={doc.Name} />
                {open ? <ExpandLess /> : <ExpandMore />}
            </ListItem>
            <Collapse
                key={doc.Sheets.Id}
                in={open}
                timeout='auto'
                unmountOnExit
            >
                <List component='li' disablePadding key={doc.Id}>
                    {doc.Sheets.map(sheet => {
                        return (
                            <ListItem button key={sheet.Id}>
                                <ListItemIcon>
                                    {/* <InsertDriveFileTwoToneIcon /> */}
                                </ListItemIcon>
                                <ListItemText key={sheet.Id} primary={sheet.Title} />
                            </ListItem>
                        )
                    })}
                </List>
            </Collapse>
            <Divider />
        </div>
    )
}


export default function CategoriesResults() {
    const docs = data.documents  //this coming from a json file
    return (
        <div>
            <List component='nav' aria-labelledby='nested-list-subheader'>
                {docs.map(doc => {
                    return (
                        <CustomizedListItem key={doc.id} doc={doc} />
                    )
                })}
            </List>
        </div>
    )
}

Answer 2

您的所有 ListItems 都会根据相同的状态展开。
如果 open 是true，则所有这些都进入in=true其Collapse组件，因此所有这些都被展开。
要解决这个问题，您应该将可扩展的 ListItem 提取到一个单独的组件中，该组件将管理它自己的状态：

 class CustomizedListItem extends React.Component {
  constructor(props) {
    super(props);
    this.state = {
        open: false
      };
      this.handleClick = this.handleClick.bind(this);
    }

    handleClick() {
      console.log("Handle Clicked....");
       this.setState(prevState => ({
         open: !prevState.open
       }));
    }

  render(){
  const { doc } = this.props;
  return (
    <div>
      <ListItem button key={doc.Id} onClick={this.handleClick}>
        <ListItemText primary={doc.Name} />
        {this.state.open ? <ExpandLess /> : <ExpandMore />}
      </ListItem>
      <Collapse
        key={doc.Sheets.Id}
        in={this.state.open}
        timeout='auto'
        unmountOnExit
      >
      <List component='li' disablePadding key={doc.Id}>
        {doc.Sheets.map(sheet => {
          return (
            <ListItem button key={sheet.Id}>
              <ListItemIcon>
                {/* <InsertDriveFileTwoToneIcon /> */}
              </ListItemIcon>
              <ListItemText key={sheet.Id} primary={sheet.Title} />
            </ListItem>
          );
        })}
      </List>
    </Collapse>
    <Divider />
    </div>
    )
  }
}

export default class CategoriesResults extends React.Component {
  render() {
    const docs = data.documents;  //this coming from a json file, please see below for the sample json
     return (
      <div>
        <List component='nav' aria-labelledby='nested-list-subheader'>
          {docs.map(doc => {
            return (
              <CustomizedListItem key={doc.id} doc={doc} />
            );
          })}
        </List>     
      </div>
    );
  }
}

我使用了类组件，因为您在问题中使用了它。如果您想使用react-hooks看到相同的解决方案，请告诉我:)