Let us implement a custom hook to rerender a React component forcefully: function useForceRerender() { const [state, setState] = React.useState({ value: 10 }); function rerenderForcefully() { setState((prev) => { return { ...prev }; }); } return rerenderForcefully; }Code language...
As we already saw before, React re-renders a component when you call thesetStatefunction to change the state (or the provided function from theuseStatehook in function components). As a result, the child components only update when the parent component's state changeswith one of those function...
有状态的地方应该指 useState(0) 这句,不过这句和无状态 UI 组件 App 的 useCount() 很像,既然 React 把 useCount 成为自定义 Hook,那么 useState 就是官方 Hook,具有一样的定义,因此可以认为 useCount 是无状态的,useState 也是一层 renderProps,最终的状态其实是 useState 这个React 内置的组件。 我们看 r...
hook = workInProgressHook; // 更新阶段此时的hook,是初次渲染时已经建立好的hook,取出来即可。 所以,这就是为什么不能在条件语句中使用React hook。 // 将workInProgressHook往后移动一位,下次进来时的workInProgressHook就是下一个当前的hook workInProgressHook = workInProgressHook.next; } // 上述都是在...
An extension of this hook is available by importing useSocketIO: import { useSocketIO } from 'react-use-websocket'; //Same API in component const { sendMessage, lastMessage, readyState } = useSocketIO( 'http://localhost:3000/' ); It is important to note that lastMessage will not be...
可以看到,这样不仅没有占用组件自己的 state,也不需要手写 onChange 回调函数进行处理,这些处理都压缩成了一行 use hook。 实现:读到这里应该大致可以猜到了,利用useState存储组件的值,并抛出value与onChange,监听onChange并通过setValue修改value, 就可以在每次onChange时触发调用组件的 rerender 了。
Now, how do we go about updating the hook? Since we are already using a closure, let’s enclose another functionrerenderthat can do that. The finalrenderHookfunction looks like this: functionrenderHook(hook, args) {letresult = {};functionTestComponent({ hookArgs }...
import React from 'react' import ReactDOM from 'react-dom' import { useForceUpdate } from 'use-force-update-hook' function MyAwesomeComponent() { const forceUpdate = useForceUpdate() console.log('render') return ( <div> <button onClick={forceUpdate}>Click to rerender MyAwesomeComponent</but...
Can also take parameters, and the result of one can be easily be used by another hook (e.g.,setStatefromuseStateinuseEffect). Minifies way better than classes, which tend to be a bit more problematic for minifiers. Might remove HOCs and render props patterns in your app which introduced...
可以看到,这样不仅没有占用组件自己的 state,也不需要手写 onChange 回调函数进行处理,这些处理都压缩成了一行 use hook。 实现:读到这里应该大致可以猜到了,利用useState存储组件的值,并抛出value与onChange,监听onChange并通过setValue修改value, 就可以在每次onChange时触发调用组件的 rerender 了。