react-native初探——helloworld demo

import React, { Component } from ‘react‘;
import { Text, View, StyleSheet } from ‘react-native‘;

class HelloWorldApp extends Component {
  constructor(props) {
    super(props);
    this.state = { showText: true };

    // 每1000毫秒对showText状态做一次取反操作
    setInterval(() => {
      this.setState(previousState => {
        return { showText: !previousState.showText };
      });
    }, 1000);
  }
  render() {
    // 根据当前showText的值决定是否显示text内容
    let display = this.state.showText ? this.props.text : ‘ ‘;
    return (
        <View>
          <Text style={[styles.bigblue, {color: ‘red‘}]}>{display}</Text>
        </View>
    );
  }
}

export default class App extends Component {
  render() {
    return (
      <View>
        <HelloWorldApp text=‘Hello world‘ />
      </View>
    );
  }
}

const styles = StyleSheet.create({
  bigblue: {
    color: ‘blue‘,
    fontWeight: ‘bold‘,
    fontSize: 30,
  }
});