如何在React中使用钩子强制组件重新渲染?

考虑下面的钩子示例

   import { useState } from 'react';

   function Example() {
       const [count, setCount] = useState(0);

       return (
           <div>
               <p>You clicked {count} times</p>
               <button onClick={() => setCount(count + 1)}>
                  Click me
               </button>
          </div>
        );
     }

基本上，我们使用this.forceUpdate()方法强制组件立即在React类组件中重新渲染，如下例所示

    class Test extends Component{
        constructor(props){
             super(props);
             this.state = {
                 count:0,
                 count2: 100
             }
             this.setCount = this.setCount.bind(this);//how can I do this with hooks in functional component 
        }
        setCount(){
              let count = this.state.count;
                   count = count+1;
              let count2 = this.state.count2;
                   count2 = count2+1;
              this.setState({count});
              this.forceUpdate();
              //before below setState the component will re-render immediately when this.forceUpdate() is called
              this.setState({count2: count
        }

        render(){
              return (<div>
                   <span>Count: {this.state.count}></span>. 
                   <button onClick={this.setCount}></button>
                 </div>
        }
 }

但我的问题是，我如何才能强制上述功能组件重新渲染立即与挂钩?

当前回答

在Hook中有许多强制重渲染的方法。

对我来说，使用useState()和引用对象值提示的简单方法。

const [, forceRender] = useState({});

// Anywhre
forceRender({});

Codesandbox例子

2021-04-16 02:46:40

其他回答

正如其他人提到的，useState工作-这是mobx-react-lite如何实现更新-你可以做一些类似的事情。

定义一个新的钩子useForceUpdate -

import { useState, useCallback } from 'react'

export function useForceUpdate() {
  const [, setTick] = useState(0);
  const update = useCallback(() => {
    setTick(tick => tick + 1);
  }, [])
  return update;
}

并将其用于组件-

const forceUpdate = useForceUpdate();
if (...) {
  forceUpdate(); // force re-render
}

参见https://github.com/mobxjs/mobx-react-lite/blob/master/src/utils.ts和https://github.com/mobxjs/mobx-react-lite/blob/master/src/useObserver.ts

2019-04-26 06:38:42

单行解决方案:

const [,forceRender] = useReducer((s) => s+1, 0)

你可以在这里了解useReducer。 https://reactjs.org/docs/hooks-reference.html#usereducer

2020-05-11 06:15:18

你可以(ab)利用React在JSX代码中不打印布尔值的事实，使用普通钩子强制渲染

// create a hook
const [forceRerender, setForceRerender] = React.useState(true);

// ...put this line where you want to force a rerender
setForceRerender(!forceRerender);

// ...make sure that {forceRerender} is "visible" in your js code
// ({forceRerender} will not actually be visible since booleans are
// not printed, but updating its value will nonetheless force a
// rerender)
return (
  <div>{forceRerender}</div>
)

2019-07-11 11:31:37

React Hooks FAQ官方解决方案的forceUpdate:

const [_, forceUpdate] = useReducer((x) => x + 1, 0);
// usage
<button onClick={forceUpdate}>Force update</button>

工作示例

2020-01-05 17:25:40

你可以像这样简单地定义useState:

const [, forceUpdate] = React.useState(0);

和用法:forceUpdate(n => !n)

希望这对你有所帮助!

2019-07-03 04:13:50

如何在React中使用钩子强制组件重新渲染?

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