react简单父子组件传值

//父组件
import React,{Component} from 'react';
import Register from './register.js';
import List from './list.js';
class App extends Component{
  constructor(props){
    super(props)
    this.state={
      obj: [
        {name:'张三',age: 18,gender: '男',phone: '18817800121'},
        {name:'李四',age: 17,gender: '女',phone: '18817800121'},
        {name:'王五',age: 16,gender: '男',phone: '18817800121'},
      ]
    }
  }
  render(){
    let list= this.state.obj;
    return(
      <div>
        <Register list={list} pfn={(data)=>this.fn(data)}/>
        <List list={list}/>
      </div>
    )
  }
  fn(data){
    this.setState({
      obj: data
    })
  }
}

export default App

// 子组件
import React, { Component } from 'react';
import './register.css'
class Register extends Component{
    constructor(props){
        super(props);
        this.state={
            name: '',
            age: '',
            gender: '女',
            phone: '',
            addDate: this.props.list
        }
        // let {name,age,gender,phone}=this.state;
    }
    render(){
        let {name,age,gender,phone}=this.state;
        return (
            <div className="register">
                <fieldset>
                    <legend>表单</legend>
                    <div>
                        <span>姓名:</span>
                        <input placeholder="请输入姓名" value={name} onChange={(e)=>this.changeName(e)}/>
                    </div>
                    <div>
                        <span>年龄:</span>
                        <input placeholder="请输入年龄" value={age} onChange={(e)=>this.changeAge(e)}/>
                    </div>
                    <div>
                        <span>性别:</span>
                        <select value={gender} onChange={(e)=>this.changeGender(e)}>
                            <option value="男">男</option>
                            <option value="女">女</option>
                        </select>
                    </div>
                    <div>
                        <span>手机:</span>
                        <input placeholder="请输入手机号" value={phone} onChange={(e)=>this.changePhone(e)}/>
                    </div>
                    <div>
                        <button onClick={()=>this.addUser()}>添加新用户</button>
                    </div>
                </fieldset>
            </div>
        )
    }
    addUser(){
        if(this.state.name!='' || this.state.age!='' || this.state.phone!=''){
            this.state.addDate.unshift({name: this.state.name,age: this.state.age,gender: this.state.gender,phone:this.state.phone});
            this.setState({});
            this.props.pfn(this.state.addDate)//这个地方把值传递给了props的事件当中
        }else {
            alert('数据不能为空')
        }
    }
    changeName(e){
        this.setState({
            name: e.target.value
        })
    }
    changeAge(e){
        this.setState({
            age: e.target.value
        })
    }
    changeGender(e){
        this.setState({
            gender: e.target.value
        })
    }
    changePhone(e){
        this.setState({
            phone: e.target.value
        })
    }

}
export default Register