我正在嘗試設置 firebase 身份驗證。我有兩個組成部分。第一個是帶有 firebase.auth().currentUser 的應用程序，我正在檢查是否有登錄用戶，然后如果有這樣的用戶，我會呈現頁面，如果沒有，我會呈現登錄頁面。第二個組件我只是從父級獲取處理程序并嘗試呈現登錄頁面?，F在我只看到空白頁和錯誤“'props' 未定義”。請幫我解決它。應用程序.jsimport React, {Component} from "react";import {    BrowserRouter as Router,    Switch,    Route,    Link} from "react-router-dom";import { Layout } from 'antd';import AddStock from './components/stocksDB/addStock';import { Typography, Menu } from 'antd';import 'antd/dist/antd.css';import './App.css';import AddClient from './components/clients/addClient.js';import PifForm from './components/clients/pif/pifForm';import KuaForm from './components/clients/pif/kuaForm';import firebase from './firebase.js';import {Login} from './components/login.js'const { Title } = Typography;const {Header, Footer, Content} = Layout;class App extends Component {    constructor(props){        super(props);        this.state = {            login: '',            password: ''        }    }    handleChange = (event) => {        const target = event.target;        const name = target.name;        this.setState({            [name]: target.value        }, () => {console.log(name, this.state)})    };    signUp = () => {        firebase.auth().createUserWithEmailAndPassword(this.state.login, this.state.password).catch(function(error) {            console.log(error);        })    };    signIn = () => {        firebase.auth().signInWithEmailAndPassword(this.state.login, this.state.password).catch(function(error) {            console.log(error);        })    };    onFinishFailed = errorInfo => {        console.log('Failed:', errorInfo);    };