Javascript can';不要在react中使用ref import React,{Component}来自“React”; 类学习扩展组件{fName=React.createRef();onForm=e=>{ e、 preventDefault();console.log(this.fName.value.value);};render(){return(Submit);}}}导出默认学习;
您必须使用ref上的Javascript can';不要在react中使用ref import React,{Component}来自“React”; 类学习扩展组件{fName=React.createRef();onForm=e=>{ e、 preventDefault();console.log(this.fName.value.value);};render(){return(Submit);}}}导出默认学习;,javascript,reactjs,Javascript,Reactjs,您必须使用ref上的current属性: console.log(this.fName.current.value) 但请考虑使用更改事件和状态 import React, { Component } from "react"; class Learning extends Component {fName = React.createRef();onForm = e => { e.preventDefault();console.log(this.fName.value.value);
current
属性:
console.log(this.fName.current.value)代码>
但请考虑使用更改事件和状态
import React, { Component } from "react";
class Learning extends Component {fName = React.createRef();onForm = e => {
e.preventDefault();console.log(this.fName.value.value);};render() {return (<div><form onSubmit={this.onForm}><inputtype="text" placeholder="Enter Your First Name" ref={this.fName} /><button type="submit" style={BtnStyle}>Submit</button></form></div>);}}export default Learning;
类学习扩展组件{
构造函数(){
此.state={
fName:“”
}
}
updateName=(e)=>{
this.setState({fName:e.target.value});
}
onForm=(e)=>{
e、 预防默认值();
console.log(this.state.fName):
}
render(){
返回(
):
}
}
再次检查react文档,使用react.createRef()
创建的引用可以像this.fName.current.XXX
一样访问
class Learning extends Component {
constructor() {
this.state = {
fName: ''
}
}
updateName = (e) => {
this.setState({fName: e.target.value});
}
onForm = (e) => {
e.preventDefault();
console.log(this.state.fName):
}
render() {
return (
<form onSubmit={this.onForm}>
<input onChange={this.updateName} />
</form>
):
}
}