例
创建Content

import React, { Component } from 'react';

class Content extends Component {

    constructor(props) {
        super(props);
    }

    render(){
        return <p>{this.props.selectName}content</p>
    }
}

export default Content;

创建comment

import React, { Component } from 'react';
import Content from './Content';

class Comment extends Component {

    constructor(props) {
        super(props);
        this.state = {names: ["张小张","3333","2332"]
        ,selectName: '找小夏'};
        this.handleSelect = this.handleSelect.bind(this)

    }

    handleSelect(event){
        this.setState({selectName:event.target.value,
        });
    }
    render(){
        var options = [];
        for(var option in this.state.names){
            console.log(this.state.names[option]);
            options.push(<option value={this.state.names[option]}>{this.state.names[option]}</option>)
        }
        console.log(options.toString())
        return <div>
            <select onChange={this.handleSelect}>
                {options}
            </select>
            <Content selectName={this.state.selectName}></Content>
        </div>
    }
}

export default Comment;