如何从app.js调用子组件函数，该组件是在React Native中用for循环创建的？

Question

我要调用子组件函数，该子组件函数是通过app.js文件中的for循环创建的。

这是我的app.js;

import React, { Component } from 'react';
import { View, Button } from 'react-native';

export default class App extends Component {
    constructor(props) {
        super(props);
        const fields = [];
        for (let i = 0; i < assets.fieldNames[assets.systemLang].length; i++) {
            fields.push(
                <InfoField
                    key={i}
                    title={assets.fieldNames[assets.systemLang][i]}
                    value="" />
            );
        };
        this.state = {
            fields,
        };
    }

    callFunctionFromInfoField = (id) => {
        const fields = [...this.state.fields];
        fields[id].showAlert(); /// ** I NEED SOMETHING LIKE THIS **
    }

    render() {
        return (
            <View>
                <View>
                    {
                        this.state.fields
                    }
                </View>
                <Button onPress={this.callFunctionFromInfoField(2)} />
            </View>
        );
    }
}

这是我的孩子部分；

import React, { Component } from 'react';
import { Text, TouchableOpacity,Animated } from 'react-native';

export default class InfoField extends Component {
    constructor(props) {
        super(props);
        this.state = {

        };
    }

    showAlert = () => {
        alert(`${this.props.title} is empty. Please fill it`);
    }

    render() {
        return (
            <Animated.View style={styles.container}>
                <TouchableOpacity style={{ justifyContent: "center" }}>
                    <Text style={styles.text} {...this.props}> {this.props.title} </Text>
                </TouchableOpacity>
            </Animated.View>
        );
    }
}

首先，我需要从数组中获取子组件 ，然后在其中调用showAlert函数。 有这样的蚂蚁方法吗？

fields [1] .showAlert（）;