React使用ES6语法重构组件代码

Posted 2020-12-02

首次使用react，要注意react不同版本库，是ES5还是ES6的写法，如何做到统一。下面对于ES6语法重构组件的代码如下：
（1）原始代码：

<script type="text/babel">
var destination=document.querySelector("#root");
var LightningCounter=React.createClass({
getInitialState:function(){
return {
strickes:0
}
},
timeTricks:function(){
this.setState({
strickes:this.state.strickes+100
});
},
componentDidMount:function(){
setInterval(this.timeTricks,1000)
},
render:function(){
return <h1>{this.state.strickes}</h1>;
}
});
var LightningCounterDisplay=React.createClass({
render:function(){
var distyle={
width:250,
height:250,
textAlign:"center",
backgroundColor:"black",
color:"#CCC",
borderRadius:10,
webkitFilter:"drop-shadow(0px 0px 5px #666)"
};
return <div style={distyle}>
<LightningCounter/>
</div>;
}
});

    ReactDOM.render(
        <LightningCounterDisplay/>,
        destination);
</script>

(2)重构后的代码：

<script type="text/babel">
var destination=document.querySelector("#root");

class LightningCounterDisplay extends React.Component{        
        render(){
            var distyle= {
                width:250,
                height:250,
                textAlign:"center",
                backgroundColor:"black",
                color:"#CCC",
                borderRadius:10,
                webkitFilter:"drop-shadow(0px 0px 5px #666)"
            };
            return <div style={distyle}>
            <LightningCounter/>
            </div>;
        }
}    
class LightningCounter extends React.Component{
            constructor(props){
                super(props);
                this.state={
                    numtricks:0
                }
                this.timeTotalTrick = this.timeTotalTrick.bind(this);  
                //最关键的一句是，bind让实例化的组件任何
                // 地方都能调用该函数，并且函数内部的this指向实例化的组件
            }
            timeTotalTrick(){
                this.setState({
                    numtricks:this.state.numtricks+100
                })
            }
            componentDidMount(){
                setInterval(this.timeTotalTrick,1000)
            }
            render(){
                return <div>{this.state.numtricks}</div>;
            }
    }

    ReactDOM.render(<LightningCounterDisplay/>,destination);
</script>