React为解决跨组件渲染给了一个API ReactDOM.unstable_renderSubtreeIntoContainer(parentElement,nextElement,container,callback) 其实这和ReactDOM.render的区别在于ReactDOM.render的parentElement是null。而parentElement只是提供了一个context。后续处理逻辑一致 if(parentComponent){varparentInst=ReactInstanceMap.get(paren...
return <childComponent ref={(v) => { this.childCp = v; }}/> } } 上面的childComponent被withRouter包裹过一遍后,这时候你在parentComponent中通过ref获取到的是并不会是childComponent,而是withRouter组件。这就比较尴尬了,我们大多数情况肯定是需要获取自己写的组件实例的。有一点需要讲明白:就是通过ref获取...
Get state value onClick event One method is to update state, and when a click happens, use a callback function that gives the parent component the values. Here’s an article that covers this method more in detail, “How to get form data on submit in ReactJS“. Get state value on onC...
function legacyRenderSubtreeIntoContainer ( parentComponent, children, container, forceHydrate, callback ) { // 一开始时dom元素中 不存在该属性 则需要重新创建 let root = container._reactRootContainer if (!root) { // 这就是第一件事情 root = container._reactRootContainer = legacyCreateRootFromDOM...
Get state value onClick event One method is to update state, and when a click happens, use a callback function that gives the parent component the values. Here’s an article that covers this method more in detail, “How to get form data on submit in ReactJS“. ...
Parent Component 1. 1. { }}> 1. Call Function 1. 1. 1. ) 1. } 1. Now, lets create a child component using forwardRef .A child component is ready along with a function in which it alerts a message “Child function called”, this function is named as showAlert with no argume...
importReact,{Component}from'react';importPropTypesfrom'prop-types';/**父组件 */exportdefaultclassParentextendsComponent{state={msg:0}// 声明Context属性staticchildContextTypes={// 数字类型msg:PropTypes.number,// 方法method:PropTypes.func}// 返回Context对象,约定好方法getChildContext(){return{msg:this...
1//子组件2varChild=React.createClass({3render:function(){4return(56请输入邮箱:78)9}10});11//父组件,此处通过event.target.value获取子组件的值12varParent=React.createClass({13getInitialState:function(){14return{15email:''16}17},18handleEmail:function(event){19this.setState({email:event.tar...
" />, document.getElementById('root'));在这个例子中，我们在MyComponent组件中定义了一个handle...
ReactDOM.render|=ReactMount.render(nextElement,container,callback)|=ReactMount._renderSubtreeIntoContainer(parentComponent,// scr: ---> nullnextElement,// scr: ---> ReactElement[1]container,// scr: ---> document.getElementById(‘root’)callback’// scr: ---> undefined)// scr: --->...