CommentBox.js

import React, { Component } from 'react';
import { View, Text, TextInput } from 'react-native';
import {Button, Card, CardSection } from './common';

export default class CommentBox extends Component {
    constructor(props) {
        super(props);
    }

    render() {
        return (
        <Card>
            <CardSection>
                <TextInput
                style={{flex: 1, height: 100}}
                multiline
                placeholder="Say something interesting"
                onChangeText={(text) => this.props.textChangeHandler(text)}
                />
            </CardSection>
            <CardSection>
                <Button onPress={this.props.addComment}>Comment</Button>
            </CardSection>
        </Card>
        );
    }
}

const styles = {
    textInputContainer: {
        flex: 1,
        height: 100,
        borderRadius: 5,
        borderWidth: 1,
        borderColor: '#eee',
    }
};