如何滚动到底部的反应?

我想建立一个聊天系统，并自动滚动到底部时，进入窗口，当新的消息进来。如何在React中自动滚动到容器底部?

当前回答

您可以使用引用来跟踪组件。

如果你知道如何设置单个组件的引用(最后一个)，请发布!

以下是我发现对我有用的方法:

class ChatContainer extends React.Component {
  render() {
    const {
      messages
    } = this.props;

    var messageBubbles = messages.map((message, idx) => (
      <MessageBubble
        key={message.id}
        message={message.body}
        ref={(ref) => this['_div' + idx] = ref}
      />
    ));

    return (
      <div>
        {messageBubbles}
      </div>
    );
  }

  componentDidMount() {
    this.handleResize();

    // Scroll to the bottom on initialization
    var len = this.props.messages.length - 1;
    const node = ReactDOM.findDOMNode(this['_div' + len]);
    if (node) {
      node.scrollIntoView();
    }
  }

  componentDidUpdate() {
    // Scroll as new elements come along
    var len = this.props.messages.length - 1;
    const node = ReactDOM.findDOMNode(this['_div' + len]);
    if (node) {
      node.scrollIntoView();
    }
  }
}

2016-06-03 17:54:25

其他回答

我喜欢这样做。

componentDidUpdate(prevProps, prevState){
  this.scrollToBottom();
}

scrollToBottom() {
  const {thing} = this.refs;
  thing.scrollTop = thing.scrollHeight - thing.clientHeight;
}

render(){
  return(
    <div ref={`thing`}>
      <ManyThings things={}>
    </div>
  )
}

2017-04-26 00:23:35

Reference your messages container. <div ref={(el) => { this.messagesContainer = el; }}> YOUR MESSAGES </div> Find your messages container and make its scrollTop attribute equal scrollHeight: scrollToBottom = () => { const messagesContainer = ReactDOM.findDOMNode(this.messagesContainer); messagesContainer.scrollTop = messagesContainer.scrollHeight; }; Evoke above method on componentDidMount and componentDidUpdate. componentDidMount() { this.scrollToBottom(); } componentDidUpdate() { this.scrollToBottom(); }

这是我如何在我的代码中使用这个:

 export default class StoryView extends Component {

    constructor(props) {
        super(props);
        this.scrollToBottom = this.scrollToBottom.bind(this);
    }

    scrollToBottom = () => {
        const messagesContainer = ReactDOM.findDOMNode(this.messagesContainer);
        messagesContainer.scrollTop = messagesContainer.scrollHeight;
    };

    componentDidMount() {
        this.scrollToBottom();
    }

    componentDidUpdate() {
        this.scrollToBottom();
    }

    render() {
        return (
            <div>
                <Grid className="storyView">
                    <Row>
                        <div className="codeView">
                            <Col md={8} mdOffset={2}>
                                <div ref={(el) => { this.messagesContainer = el; }} 
                                     className="chat">
                                    {
                                        this.props.messages.map(function (message, i) {
                                            return (
                                                <div key={i}>
                                                    <div className="bubble" >
                                                        {message.body}
                                                    </div>
                                                </div>
                                            );
                                        }, this)
                                    }
                                </div>
                            </Col>
                        </div>
                    </Row>
                </Grid>
            </div>
        );
    }
}

2017-02-23 13:33:55

我推荐的最简单和最好的方法是。

我的ReactJS版本:16.12.0

对于类组件

render()函数内的HTML结构

    render()
        return(
            <body>
                <div ref="messageList">
                    <div>Message 1</div>
                    <div>Message 2</div>
                    <div>Message 3</div>
                </div>
            </body>
        )
    )

scrollToBottom()函数，该函数将获取元素的引用。并根据scrollIntoView()函数滚动。

  scrollToBottom = () => {
    const { messageList } = this.refs;
    messageList.scrollIntoView({behavior: "smooth", block: "end", inline: "nearest"});
  }

并在componentDidMount()和componentDidUpdate()中调用上述函数

对于功能组件(挂钩)

导入useRef()和useEffect()

import { useEffect, useRef } from 'react'

在导出函数中，(与调用useState()相同)

const messageRef = useRef();

让我们假设页面加载时你必须滚动，

useEffect(() => {
    if (messageRef.current) {
      messageRef.current.scrollIntoView(
        {
          behavior: 'smooth',
          block: 'end',
          inline: 'nearest'
        })
    }
  })

或者，如果你想让它在执行动作时触发，

useEffect(() => {
  if (messageRef.current) {
    messageRef.current.scrollIntoView(
      {
        behavior: 'smooth',
        block: 'end',
        inline: 'nearest'
      })
  }
},
[stateVariable])

最后是HTML结构

return(
    <body>
        <div ref={messageRef}> // <= The only different is we are calling a variable here
            <div>Message 1</div>
            <div>Message 2</div>
            <div>Message 3</div>
        </div>
    </body>
)

有关Element.scrollIntoView()的更多解释，请访问developer.mozilla.org

更详细的解释在回调参考访问reactjs.org

2020-02-29 22:31:41

在上面的答案中，scrollIntoView(…)方法有两个主要问题:

it's semantically incorrect, as it causes the entire page to scroll if your parent element is scrolled outside the window boundaries. The browser literally scrolls anything it needs to in getting the element visible. in a functional component using useEffect(), you get unreliable results, at least in Chrome 96.0.4665.45. useEffect() gets called too soon on page reload and the scroll doesn't happen. Delaying scrollIntoView with setTimeout(..., 0) fixes it for page reload, but not first load in a fresh tab, at least for me. shrugs

这是我一直在使用的解决方案，它很可靠，而且更兼容旧的浏览器:

function Chat() {
   const chatParent = useRef<HTMLDivElement(null);

   useEffect(() => {
      const domNode = chatParent.current;
      if (domNode) {
         domNode.scrollTop = domNode.scrollHeight;
      }
   })
   return (
      <div ref={chatParent}>
         ...
      </div>
   )
}

2021-11-23 20:55:32

我在消息的末尾创建了一个空元素，并滚动到该元素。不需要跟踪裁判。

2016-12-26 11:44:07

如何滚动到底部的反应?

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