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

潜在的选项是仅在特定组件上使用键强制更新。更新键会触发组件的呈现(之前更新失败)

例如:

const [tableKey, setTableKey] = useState(1);
...

useEffect(() => {
    ...
    setTableKey(tableKey + 1);
}, [tableData]);

...
<DataTable
    key={tableKey}
    data={tableData}/>

2019-07-14 19:25:20

其他回答

我对forceUpdate的变化不是通过计数器，而是通过一个对象:

// Emulates `forceUpdate()`
const [unusedState, setUnusedState] = useState()
const forceUpdate = useCallback(() => setUnusedState({}), [])

因为{}!=={}每次。

2019-11-21 13:01:56

潜在的选项是仅在特定组件上使用键强制更新。更新键会触发组件的呈现(之前更新失败)

例如:

const [tableKey, setTableKey] = useState(1);
...

useEffect(() => {
    ...
    setTableKey(tableKey + 1);
}, [tableData]);

...
<DataTable
    key={tableKey}
    data={tableData}/>

2019-07-14 19:25:20

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-tidy有一个自定义钩子，叫做userfresh:

import React from 'react'
import {useRefresh} from 'react-tidy'

function App() {
  const refresh = useRefresh()
  return (
    <p>
      The time is {new Date()} <button onClick={refresh}>Refresh</button>
    </p>
  )
}

了解更多关于这个钩子

我是这个库的作者。

2020-10-08 13:49:41

我在使用一个数组时发现了这个问题。然而，我发现了另一种方法，而不是显式的forceUpdate——解构一个数组，并使用下面的代码为它设置一个新值:

    setRoutes(arr => [...arr, newRoute]); // add new elements to the array
    setRouteErrors(routeErrs => [...routeErrs]); // the array elements were changed

我发现非常有趣的是，即使设置一个数组的副本也不会触发钩子。我认为React只做了浅层的比较

2022-08-18 16:40:39

如何在React中使用钩子强制组件重新渲染?

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