[React] How to use a setState Updater Function with a Reducer Pattern

【[React] How to use a setState Updater Function with a Reducer Pattern】的更多相关文章

[React] How to use a setState Updater Function with a Reducer Pattern

In this lesson we'll walk through setting up an updater function that can receive an action argument. We'll also dive into how to separate your state management logic into a separate reducer function much like how Redux operates. It will receive an a…

React源码解析：setState

先来几个例子热热身: ......... constructor(props){ super(props); this.state = { index: 0 } } componentDidMount() { this.setState({ index: this.state.index + 1 }); console.log(this.state.index); this.setState({ index: this.state.index + 1 }); console.log(this.s…

React与Preact差异之 -- setState

Preact是React的轻量级实现,是React比较好的替代者之一,有着体积小的优点,当然与React之间一定会存在实现上的差异,本文介绍了在 setState 方面的差异之处. 源码分析首先来分析下React以及Preact在setState部分的具体实现. (太长不看想偷懒,可以直接下翻看结论) React 关键代码: setState 阶段: // ReactUpdateQueue.js enqueueSetState: function(publicInstance, partial…

react native 打包Ignoring return value of function declared with warn_unused_result attribute

从 github上下载项目用于学习查看别人的代码, 当执行完npm install 用xcode 打开发现俩个错误提示Ignoring return value of function declared with warn_unused_result attribute 有俩处报了这个错误. 经一翻查找问题后发现原因是这个是版本更新方法弃用的警告,RCTSRWebSocket.m 处理方式有俩种 : 1,Xcode 做降级处理,当然好不容易升级到Xcode8.0 ,在降级…

（文章也有问题，请自行跳过）react中的状态机每次setState都是重新创建新的对象，如需取值，应该在render中处理。

demo如下 class Demo4StateLearn extends React.Component { constructor(props) { super(props); this.state = { a:11 }; this.a = this.state.a;//在创建该组件的时候就设置 this.a = 状态机.a } loadData(e) {//每次输入改变状态机 const value = e.target.value; this.setState({a:value}); }…

JavaScript Patterns 4.8 Function Properties - A Memoization Pattern

Gets a length property containing the number of arguments the function expects: function func(a, b, c) {} console.log(func.length); var myFunc = function () { // serialize the arguments object as a JSON string and use that string as a key in your cac…

type Props={};

Components Learn how to type React class components and stateless functional components with Flow Search docs Adding Flow types to your React components is incredibly powerful. After typing your component, Flow will statically ensure that you are usi…