1. es6 writing method. Initializing the default state is done in the constructor

constructor() { super(); this.state = { } }

2. If you want to use this in the event callback function, you need to bind it manually

// 方法1 this.moveElment.bind(this); // 方法2 moveElement = event => { } // 方式3 
 this.moveElement}>

getInitialState is how it is written in ES5.
In ES6, state initialization should be placed in the constructor.

class Demo extends Component{ constructor(){ super(); // 必须先调用super, 后面才能用 this this.state = {} } }

The error is clearly written, only use it

React.createClass()

getInitialStatecan only be used when, and used when creating using ES6’sclasskeyword

this.state = {}