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

这是根据上面的答案修改的,以支持“children”而不是数据数组。

注意:样式化组件的使用对于解决方案并不重要。

import {useEffect, useRef} from "react";
import React from "react";
import styled from "styled-components";

export interface Props {
    children: Array<any> | any,
}

export function AutoScrollList(props: Props) {
    const bottomRef: any = useRef();

    const scrollToBottom = () => {
        bottomRef.current.scrollIntoView({
            behavior: "smooth",
            block: "start",
        });
    };

    useEffect(() => {
        scrollToBottom()
    }, [props.children])

    return (
        <Container {...props}>
            <div key={'child'}>{props.children}</div>
            <div key={'dummy'} ref={bottomRef}/>
        </Container>
    );
}

const Container = styled.div``;

其他回答

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。

不使用findDOMNode

带有ref的类组件

class MyComponent extends Component {
  componentDidMount() {
    this.scrollToBottom();
  }

  componentDidUpdate() {
    this.scrollToBottom();
  }

  scrollToBottom() {
    this.el.scrollIntoView({ behavior: 'smooth' });
  }

  render() {
    return <div ref={el => { this.el = el; }} />
  }
}

带钩子的功能组件:

import React, { useRef, useEffect } from 'react';

const MyComponent = () => {
  const divRef = useRef(null);

  useEffect(() => {
    divRef.current.scrollIntoView({ behavior: 'smooth' });
  });

  return <div ref={divRef} />;
}

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>
   )
}

完整版(Typescript):

import * as React from React 导出类DivWithScrollHere扩展React。组件<any, any> { loading:any = React.createRef(); componentDidMount () { this.loading.scrollIntoView(假); } 呈现(){ 回报( <div ref={e =>{这个。装载= e;}}> <LoadingTile /> </div> . txt ) } }

我不能得到以下任何答案的工作,但简单的js为我做的伎俩:

  window.scrollTo({
  top: document.body.scrollHeight,
  left: 0,
  behavior: 'smooth'
});