react 解决this指向的5个方法

1

var that = this

2

fun=()=>{}
<div onClick={this.fun}></div>

3

fun(){}
<div onClick={this.fun.bind(this)}></div>

4

 constructor(props) {
        super(props);
       this.fun=this.fun.bind(this)
    }
fun(){}
<div onClick={this.fun}></div>

5

fun=()=>{}
<div onClick={()=>{this.fun}></div>