react 跟踪表单的值

//跟踪表单的值
import React, { Component } from 'react';

class FlavorForm extends Component {
    constructor(props) {
      super(props);
      this.state = {value: ''};
   
      this.handleChange = this.handleChange.bind(this);
      this.handleSubmit = this.handleSubmit.bind(this);
    }
   
    //用onChange选择方法获取select用户点击的value，并赋给state
    handleChange(event) {
      this.setState({value: event.target.value});
    }
   
    //onSubmit事件获取state中的值
    handleSubmit(event) {
      console.log(this.state.value)
      event.preventDefault();
    }
   
    render() {
      return (
        <form onSubmit={this.handleSubmit}>
          <label>
            选择您最喜欢的网站
            <select value={this.state.value} onChange={this.handleChange}>
              <option value="Google">Google</option>
              <option value="Runoob">Runoob</option>
              <option value="Taobao">Taobao</option>
              <option value="Facebook">Facebook</option>
            </select>
          </label>
          <input type="submit" value="提交" />
        </form>
      );
    }
  }

  export default FlavorForm