kangaroo/js/page/MainPage.js

import React from "react"
import { View ,Text,StyleSheet} from "react-native"

export default class MainPage extends React.Component{
    render(){
        return (
            <View style={styles.container}>
                <Text>MainPage</Text>
            </View>
        )
    }
}
const styles = StyleSheet.create({
    container:{
        flex:1,
        justifyContent:"center",
        alignItems:"center",
        backgroundColor:"#f00"
    }
})