In a function component with hooks however, setting state inside the function body (which runs at re-render similarly to the render method in class components) would not be an issue, because the function component just bails out of re-renders when it sees that the state is identical to the...
骚写法多，functional组件更符合React编程思想等等等。更具体的可以拜读dan大神的blog。其中Function ...
It's not really a feature I use often. dispatch function updates This one's a little bit more complicated. The easiest way to explain what it's for is by showing an example. Let's say that before we can update our count state, we need to do something async: function DelayedCounter(...
我试图从API获取数据并用数据设置状态,但是当我使用子组件中的数据时,我得到了一个[Unhandled promise rejection: TypeError: null is not an object这是我想要做的一个要点。有人知道为什么会发生这种情况吗?我认为这是因为数据不是从API接收的。我尝试添加一个"isLoading“状态,并仅在其为false时返回Child...
This is also work for dispatch, but state value is not updated yet on callback function. import React, { useState } from "react"; const CallBackTest = () => { const [trueFalse, setTrueFalse] = useState(false); const callBacksetState = async (data, callBackFunc) => { await setTr...
I've noticed that the "setState" function returned by the useState hook doesn't have an "afterRender" callback (the second argument of this.setState in classes) I didn't find further informations about this in the doc. Is there any design reason why the "afterRender" callback is not pr...
the purpose of this is to bring the developer's attention to lifestate function that are non-idempotent, because these might cause problems when concurrent mode is rolled out. So, I'm assuming just ignoring double renders that cause double sideeffects in StrictMode is not a good idea for futu...
If instead it's working as intended how I can retrieve the updated status? Which versions of React, and which browser / OS are affected by this issue? Did this work in previous versions of React? 16.7.0-alpha.0 another way does not use useRef is that you define a variable outside the...