React中的ref属性的使用示例详解

const domCom = <button type="button">button</button>;
const refDom = ReactDOM.render(domCom，container);
//ConfirmPass的组件内容省略
const refCom = ReactDOM.render(<ConfirmPass/>,container);
console.log(refDom);
console.log(refCom);

import React, { Component } from 'react'

export default class index extends Component {
  showData = () => {
    // 获取input节点
    const { inputRef } = this.refs

    // 输出input值
    console.log(inputRef.value);
  }
  render() {
    return (
      <div>
        <input ref="inputRef" type="text" placeholder="点击按钮提示数据"/>&nbsp;
        <button onClick={ this.showData }>点我提示输入框值</button>
      </div>
    )
  }
}

import React, { Component } from 'react'

export default class index extends Component {
// React.createRef调用后返回一个容器，存储被ref标识的节点，单一使用。也就是说，没定义一个ref就要调用一次React.createRef
  inputRef = React.createRef()

  showData = () => {
    const refVal = this.inputRef.current

    console.log(refVal.value);
  }
  render() {
    return (
      <div>
        <input ref={ this.inputRef } type="text" placeholder="点击按钮提示数据"/>&nbsp;
        <button onClick={ this.showData }>点我提示输入框值</button>
      </div>
    )
  }
}

import React, { Component } from 'react'

export default class index extends Component {
  showData = () => {
    const { inputRef } = this

    console.log(inputRef.value);
  }
  render() {
    return (
      <div>
        {/* 这里传入一个回调函数 */}
        <input ref={ currentNode => this.inputRef = currentNode } type="text" placeholder="点击按钮提示数据"/>&nbsp;
        <button onClick={ this.showData }>点我提示输入框值</button>
      </div>
    )
  }
}