16.3.0之前的设置方法为

var HelloMessage = React.createClass({
    childMethod: function(){
        alert("组件之间通信成功");
    },
    render: function() {
        return <div> <h1>Hello {this.props.name}</h1>  <button onClick={this.childMethod}>子组件</button></div>
    }
});

// 父组件
var ImDaddyComponent = React.createClass({
    getDS: function(){
        // 调用组件进行通信
        this.refs.getSwordButton.childMethod();
    },
    render: function(){
        return (
                <div>
                    <HelloMessage name="John" ref="getSwordButton" />
                    <button onClick={this.getDS}>父组件</button>
                </div>
        );
    }
});

ReactDOM.render(
        <ImDaddyComponent  />,
        document.getElementById('correspond')
);

16.3.0之后(包括16.3.0 version)的设置方法为

import React, {Component} from 'react';

export default class Parent extends Component {
    render() {
        return(
            <div>
                <Child onRef={this.onRef} />
                <button onClick={this.click} >click</button>
            </div>
        )
    }

    onRef = (ref) => {
        this.child = ref
    }

    click = (e) => {
        this.child.myName()
    }

}

class Child extends Component {
    componentDidMount(){
        this.props.onRef(this)
    }

    myName = () => alert('xiaohesong')

    render() {
        return ('woqu')
    }
}