您缺少构造函数中的绑定，
props如果您没有在构造函数中使用它们，也不需要通过。另外你还需要
import { PropTypes } from'react'class SearchBar extends React.Component { constructor() { super(); this.handler = this.handler.bind(this); } handler(e){ this.props.filterUser(e.target.value); } render () { return ( <div> <input type='text' className='from-control search-bar' placeholder='Search' onChange={this.handler} /> </div> ); }}export default class User extends React.Component { constructor() { super(); this.filterUser = this.filterUser.bind(this); this.state = { name: '', age: '', filter: '' }; } filterUser(filterValue){ this.setState({ filter: filterValue }); } render() { return ( <div> <SearchBar filterUser={this.filterUser} /> <span>Value: {this.state.filter}</span> </div> ); }}
