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
}
});
Julen的解决方案有点难以阅读,这里有更清晰和准确的反应代码,供那些根据标题而不是问题的微小细节绊倒他的人使用。
Tl;dr版本:当你要更新到观察者发送调用一个调度方法,反过来实际上会通知观察者(或执行ajax等)
使用示例组件jsfiddle完成jsfiddle
var InputField = React.createClass({
getDefaultProps: function () {
return {
initialValue: '',
onChange: null
};
},
getInitialState: function () {
return {
value: this.props.initialValue
};
},
render: function () {
var state = this.state;
return (
<input type="text"
value={state.value}
onChange={this.onVolatileChange} />
);
},
onVolatileChange: function (event) {
this.setState({
value: event.target.value
});
this.scheduleChange();
},
scheduleChange: _.debounce(function () {
this.onChange();
}, 250),
onChange: function () {
var props = this.props;
if (props.onChange != null) {
props.onChange.call(this, this.state.value)
}
},
});
看点:
import {useState} from "react";
const useDebounce = ({defaultTimeout = 250, defaultIdentifier = 'default'} = {}) => {
const [identifiers, setIdentifiers] = useState({[defaultIdentifier]: null});
return ({fn = null, identifier = defaultIdentifier, timeout = defaultTimeout} = {}) => {
if (identifiers.hasOwnProperty(identifier)) clearTimeout(identifiers[identifier]);
setIdentifiers({...identifiers, [identifier]: setTimeout(fn, timeout)});
};
};
export default useDebounce;
并在任何地方使用它(在同一个文件中使用标识符以防止并发),例如:
const debounce = useDebounce();
const handlerA = () => {
debounce({fn: () => console.log('after 2000ms of last call with identifier A'), identifier: 'A', timeout: 2000});
};
const handlerB = () => {
debounce({fn: () => console.log('after 1500ms of last call with identifier B'), identifier: 'B', timeout: 1500});
};
下面是一个使用@Abra方法封装在函数组件中的代码片段
(我们使用织物的UI,只是用一个简单的按钮替换它)
import React, { useCallback } from "react";
import { debounce } from "lodash";
import { PrimaryButton, DefaultButton } from 'office-ui-fabric-react/lib/Button';
const debounceTimeInMS = 2000;
export const PrimaryButtonDebounced = (props) => {
const debouncedOnClick = debounce(props.onClick, debounceTimeInMS, { leading: true });
const clickHandlerDebounced = useCallback((e, value) => {
debouncedOnClick(e, value);
},[]);
const onClick = (e, value) => {
clickHandlerDebounced(e, value);
};
return (
<PrimaryButton {...props}
onClick={onClick}
/>
);
}