React.js 中的功能组件内部去抖

Question

尝试在具有随变化更新的输入字段的 React 组件上创建延迟。

代码如下：

import React from 'react'; 
import Input from "@material-ui/core/Input";
import {debounce} from "lodash";
...

const SampleRow = () => {
    let [newFriend, setNewFriend] = React.useState({name: '', lastSeen: '', contactIn: ''});

    const onAddFriend = debounce(() => {
        if(newFriend.name.length === 0){
            return;
        }
        console.log(newFriend.name);
    }, 2000);

    return (
        <TableRow>
            <TableCell component="th" scope="row">
                <Input
                    value={newFriend.name}
                    onChange={(event) => {
                        setNewFriend({...newFriend, name: event.target.value});
                        onAddFriend();
                    }}
                    placeholder={"Add friend"}
                    disableUnderline={true}
                />
            </TableCell>
            <TableCell align="left">{newFriend.lastSeen ? newFriend.lastSeen : ''}</TableCell>
            <TableCell align="left">{newFriend.contactIn ? newFriend.contactIn : ''}</TableCell>
            <TableCell align="left" className={classes.externalLinks}/>
        </TableRow>
    )
};

发生的事情是 console.log 打印出每个更改（在 2 秒超时后），并且不会取消之前的触发器。

问题是为什么会这样？以及如何解决这个问题？

I've found similar questions with complex useDebounce logic or class-components. Didn't find a reference for this problem.

Answer 1

再见，尝试取消之前的触发：

import React from 'react'; 
import Input from "@material-ui/core/Input";
import {debounce} from "lodash";
...

const SampleRow = () => {
  let [newFriend, setNewFriend] = React.useState({name: '', lastSeen: '', contactIn: 
''});

const onAddFriend = debounce((abort) => {
    if(abort){
        return;
    }
    console.log(newFriend.name);
}, 2000);

return (
    <TableRow>
        <TableCell component="th" scope="row">
            <Input
                value={newFriend.name}
                onChange={(event) => {
                    setNewFriend({...newFriend, name: event.target.value});
                    let abort = false;
                    if(event.target.value.length === 0){
                      abort = true;
                    }
                    onAddFriend(abort);
                }}
                placeholder={"Add friend"}
                disableUnderline={true}
            />
        </TableCell>
        <TableCell align="left">{newFriend.lastSeen ? newFriend.lastSeen : ''}</TableCell>
        <TableCell align="left">{newFriend.contactIn ? newFriend.contactIn : ''}</TableCell>
        <TableCell align="left" className={classes.externalLinks}/>
    </TableRow>
)
  };

Answer 2

试试这个。它将始终检查队列中现有的 debounced，并取消它发现任何。参考：

Answer 3

这里的问题是在每次渲染时都会重新创建去抖功能。

解决此问题的一种方法是将其移出功能组件。另一种方法是将您的组件更改为 Class 组件并将去抖功能保存为属性.

const { useState } = React
const { debounce } = _;

const onAddFriend = debounce(console.log, 2000);

const App = () => {
 
  const [newFriend, setNewFriend] = useState({name: '',   lastSeen: '', contactIn: ''});
  
  const handleInput = (event) => {
    setNewFriend({...newFriend, name: event.target.value});
    onAddFriend(event.target.value);
  }
  
  return (
    <div className="box">
      <form className="form">
        <div class="field">
          <label for="name-1">Update  {newFriend.name}</label>
          <div class="control">
            <input type="text" name="name-1" value={newFriend.name}
                    onChange={handleInput} class="input"/>
          </div>
        </div>
      </form>
    </div>
  )
}

ReactDOM.render(<App />,
document.getElementById("root"))

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.19/lodash.min.js"></script>
<script src="https://unpkg.com/react@16.7.0-alpha.0/umd/react.production.min.js"></script>
<script src="https://unpkg.com/react-dom@16.7.0-alpha.0/umd/react-dom.production.min.js"></script>

<div id="root"></div>

React.js 中的功能组件内部去抖

Debounce inside functional component in React.js

javascript

reactjs

react-hooks

lodash

debounce