my React demo 2

《my React demo 1》

增加一个点击计数。

1. initialize

    

constructor() {
    /// this code
}

    1) bind this

super();

    2）vector

      this.state

this.state = {iCount: 0};

    3) bind value

    Binds the value to the specified method.

this.myClick = this.myClick.bind(this);

2. ACC

        alert(this.state.iCount);
        this.state.iCount++;

update code:

import React, { Component } from 'react';

class Count extends Component {
    
    constructor() {
        super();
        this.state = {iCount: 0};
        
        this.myClick = this.myClick.bind(this);
    }
    
    myClick() {        alert(this.state.iCount);
        this.state.iCount++;

    }
    
    render() {
        return(
            <div>
                <button onClick={this.myClick}>Click me</button>
            </div>
        );
    }
}

export default Count;

Count.js