我正在尝试开发一个React原生APP。
我对Java和PHP非常有经验，但有些事情让我对react-native感到困惑。
基本上，我试图获得一个工作的登录页面（只是为了实际练习），但当我试图从子组件值（例如，密码输入）传递值到父组件函数（LoginForm）时，我很挣扎。
下面是一个具体的代码：[PasswordInput]

import * as React from 'react';
import { View } from 'react-native';
import { HelperText, TextInput } from 'react-native-paper';

class PasswordInput extends React.Component {
    constructor(props){
        super(props);
        this.state ={
            password:''
        };
    }
    getPassword() {
        return this.state.password;
    }

    login(){
        alert(this.state.password)
    }

    OnChangesValue(e){
        console.log(e.nativeEvent.text);
        this.setState({
            userName :e.nativeEvent.text,
        })
    }

    changePassword(e){
        console.log(e.nativeEvent.text);
        this.setState({
            password :e.nativeEvent.text,
        })
    }

    hasErrors(text){
        let result=true;
        if(text.length>10 || text.length==0){
            result=false;
        }
        return result;
    };

    render() {
        return (
            <View>
                <TextInput
                    ref="pass"
                    name="password"
                    onChange={this.changePassword.bind(this)}
                    secureTextEntry={true}
                    label="Password"
                    left={<TextInput.Icon name="lock" onPress={() => {
                    }}/>}
                />
                <HelperText type="error" visible={this.hasErrors(this.state.password)}>
                    Password too short!
                </HelperText>
            </View>
        );
    }
}

export default PasswordInput;

字符串
这里是LoginForm组件：

import * as React from 'react';
import { Component, createRef } from "react";
import {View, StyleSheet} from 'react-native';
import {Button, Card, Title} from 'react-native-paper';
import EmailInput from './login_components/email_input';
import PasswordInput from './login_components/password_input';
import {useRef} from 'react/cjs/react.production.min';

class LoginForm extends React.Component {

    passwordInput = createRef();

    submitForm(){
        alert(this.passwordInput['password'].value);
    }

    render() {
        return (
            <Card style={styles.detailRowContainer}>
                <Card.Title
                    title="Signup!"
                    subtitle="Inserisci i tuoi dati per eseguire il login"
                />
                <EmailInput/>
                <PasswordInput ref={this.passwordInput}/>
                <Card.Actions>
                    <Button mode="contained" type="submit" style={styles.loginButtonSection} onPress={() => this.submitForm()}>
                        LOGIN
                    </Button>
                </Card.Actions>
            </Card>
        );
    }
}

const styles = StyleSheet.create({
    loginButtonSection: {
        width: '100%',
        height: '30%',
        justifyContent: 'center',
        alignItems: 'center'
    },
    detailRowContainer: {
        flex:1,
        flexDirection:'row',
        alignItems:'center',
        justifyContent:'center'
    },
});
export default LoginForm;

型
我的目标（目前）是了解如何在LoginForm组件中接收PasswordInput值，以便在alert（submitForm（）函数）中打印密码。