如何在React.js中执行debounce ?
我想撤消handleOnChange。
我尝试debounce(这。handleOnChange, 200)但它不起作用。
function debounce(fn, delay) {
var timer = null;
return function() {
var context = this,
args = arguments;
clearTimeout(timer);
timer = setTimeout(function() {
fn.apply(context, args);
}, delay);
};
}
var SearchBox = React.createClass({
render: function() {
return <input type="search" name="p" onChange={this.handleOnChange} />;
},
handleOnChange: function(event) {
// make ajax call
}
});
扩展useState钩子
import { useState } from "react";
import _ from "underscore"
export const useDebouncedState = (initialState, durationInMs = 500) => {
const [internalState, setInternalState] = useState(initialState);
const debouncedFunction = _.debounce(setInternalState, durationInMs);
return [internalState, debouncedFunction];
};
export default useDebouncedState;
使用钩
import useDebouncedState from "../hooks/useDebouncedState"
//...
const [usernameFilter, setUsernameFilter] = useDebouncedState("")
//...
<input id="username" type="text" onChange={e => setUsernameFilter(e.target.value)}></input>
https://trippingoncode.com/react-debounce-hook/
您可以使用引用变量来存储计时器,然后将其清除。下面是一个不使用任何第三方包在react中实现deboundation的例子
import { useState, useRef } from "react";
import "./styles.css";
export default function App() {
// Variables for debouncing
const [text, setText] = useState("");
const timer = useRef();
// Variables for throtteling
const [throttle, setThrottle] = useState(false)
const handleDebouncing = ({ target }) => {
clearTimeout(timer.current)
timer.current = setTimeout(() => {
callApi();
}, 300);
setText(target.value);
};
const handleThrottleing = () => {
callApi()
setThrottle(true)
setTimeout(() => {
setThrottle(false)
}, 2000)
}
const callApi = () => {
console.log("Calling Api");
};
return (
<div className="App">
<input type="text" onChange={handleDebouncing} />
<button onClick={handleThrottleing} disabled={throttle} >Click me to see throtteling</button>
</div>
);
}
I was searching for a solution to the same problem and came across this thread as well as some others but they had the same problem: if you are trying to do a handleOnChange function and you need the value from an event target, you will get cannot read property value of null or some such error. In my case, I also needed to preserve the context of this inside the debounced function since I'm executing a fluxible action. Here's my solution, it works well for my use case so I'm leaving it here in case anyone comes across this thread:
// at top of file:
var myAction = require('../actions/someAction');
// inside React.createClass({...});
handleOnChange: function (event) {
var value = event.target.value;
var doAction = _.curry(this.context.executeAction, 2);
// only one parameter gets passed into the curried function,
// so the function passed as the first parameter to _.curry()
// will not be executed until the second parameter is passed
// which happens in the next function that is wrapped in _.debounce()
debouncedOnChange(doAction(myAction), value);
},
debouncedOnChange: _.debounce(function(action, value) {
action(value);
}, 300)