React 子组件给父组件传值、整个组件、方法
一、准备工作
1.定义一个父组件，名字为Parent
/src/component/Parent.js
import React, {Component} from 'react'
export default class Parent extends Component {
constructor(props) {
super(props)
this.state = {
name: '我是父组件',
msg: '父组件传值给子组件'
}
}
render() {
return ( <div> <h2>{ this.state.name }</h2> </div> )
} }
2.定义一个子组件 ，名字为Children
/src/component/Children.js
import React, {Component} from 'react'
export default class Children extends Component {
constructor(props) {
super(props)
this.state = {
name: '我是子组件',
msg: '子组件传值给父组件'
} }
render() {
return ( <div> <h2>{ this.state.name }</h2> </div> )
} }
3.先在App.js里引入父组件Parent
/src/App.js
import React from 'react';
import Parent from './component/Parent'
function App() {
return ( <div> <Parent/> </div> );
}
export default App;
运行项目：
编译成功
界面如图所示，http://localhost:3000/
4.父组件Parent引入子组件Children
import React, {Component} from 'react'
import Children from './Children'
export default class Parent extends Component {
constructor(props) {
super(props)
this.state = {
name: '我是父组件',
msg: '父组件传值给子组件'
} }
render() {
return ( <div> <h2>{ this.state.name }</h2> <h3>我要引入子组件了：</h3> <hr/> <Children/> </div> )
} }
已成功引入子组件
二、子组件Children传值(msg)给父组件Parent
子组件传值给父组件的步骤：
- 父组件在调用子组件时，传入一整个组件给子组件<Children parent={ this } />
- 父组件中定义一个方法getChildrenMsg(resulet, msg)，用来获取子组件传来的值以及执行其他操作
- 子组件在通过this.props来获取到一整个组件this.props.parent或者this.props[parent]
- 子组件调用父组件步骤2里定义的方法，通过bind绑定传值
Parent:
import React, {Component} from 'react'
import Children from './Children'
export default class Parent extends Component {
constructor(props) { super(props)
this.state = {
name: '我是父组件',
msg: '父组件传值给子组件',
childrenMsg: ''
} }
getChildrenMsg = (result, msg) => {
// console.log(result, msg)
// 很奇怪这里的result就是子组件那bind的第一个参数this，msg是第二个参数
this.setState({
childrenMsg: msg
}) }
render() {
return (
<div> <h2>{ this.state.name }</h2>
<h3>子组件传来的值为：{ this.state.childrenMsg }</h3>
<h3>我要引入子组件了：</h3> <hr/>
<Children parent={ this } /> </div>
) } }
Children:
import React, {Component} from 'react'
export default class Children extends Component {
constructor(props) {
super(props)
this.state = {
name: '我是子组件',
msg: '子组件传值给父组件'
} }
toParent = () => {
// console.log(this.props.parent.getChildrenMsg.bind(this, this.state.msg))
this.props.parent.getChildrenMsg(this, this.state.msg) }
render() {
return (
<div> <h2>{ this.state.name }</h2>
<button onClick={ this.toParent }>子组件传入给父组件</button> </div>
)
} }
三、子组件Children给父组件Parent传一整个组件（父组件获取整个子组件）
子组件给父组件传一整个组件（父组件获取整个子组件）的步骤：
- 父组件在调用子组件时，通过ref属性，拿到整个子组件<Children ref='children'>
- 父组件中通过this.refs.children或者this.refs[children]获取到一整个子组件实例（注意，要在DOM加载后才能获取）
Parent:
import React, {Component} from 'react'
import Children from './Children'
export default class Parent extends Component {
constructor(props) {
super(props)
this.state = {
name: '我是父组件',
msg: '父组件传值给子组件', childrenMsg: ''
} }
getChildrenMsg = () => {
this.setState({
childrenMsg: this.refs['children'].state.msg
})
}
render() {
return (
<div>
<h2>{ this.state.name }</h2>
<button onClick={ this.getChildrenMsg }>获取更新子组件的msg值</button>
<h3>子组件传来的值为：{ this.state.childrenMsg }</h3> <h3>我要引入子组件了：</h3>
<hr/>
<Children ref="children" /> </div>
)
} }
Children:
import React, {Component} from 'react'
export default class Children extends Component {
constructor(props) {
super(props)
this.state = {
name: '我是子组件',
msg: '子组件传值给父组件'
} }
render() {
return (
<div> <h2>{ this.state.name }</h2>
<h3>子组件的msg为：{ this.state.msg }</h3> </div>
)
} }
初始页面，点击按钮
点击按钮后
四、子组件Children给父组件Parent传方法
在第三点获取到整个组件的前提上，再获取方法，所以不详细讲了。
https://www.jianshu.com/p/ccc15c5963c4
以上是 React 子组件给父组件传值、整个组件、方法 的全部内容， 来源链接： utcz.com/z/383787.html
