Flex布局介绍
/**
 * Sample React Native App
 * https://github.com/facebook/react-native
 * @flow
 */
'use strict'
import React, {Component} from 'react';
import {
    AppRegistry,
    StyleSheet,
    Text,
    View
} from 'react-native';
//import {AppRegistry,} from 'react-native';
//import Day0718 from './componets/Home'

export default class Day0718 extends Component {

    render() {
        return (
            <View style={styles.Container}>
                <View style={[styles.item ,styles.itemOne]}>
                    <Text style={styles.itemText}>1</Text>
                </View>
                <View style={[styles.item ,styles.itemTwo]}>
                    <Text style={styles.itemText}>2</Text>
                </View>
                <View style={[styles.item ,styles.itemThree]}>
                    <Text style={styles.itemText}>3</Text>
                </View>
            </View>
        );
    }
}
const styles = StyleSheet.create({
    item:{
        backgroundColor:'#fff',
        borderWidth:1,
        borderColor:'#6435c9',
        margin:6,
        flex:1,
    },
    itemOne:{
      //  alignSelf:'flex-start',
    },
    itemTwo:{
        //alignSelf:'center',
    },
    itemThree:{
        flex:2,
    },
    itemText:{
        fontSize:33,
        fontFamily:'Helvetica Neue',
        fontWeight:'200',
        color:'#6435c9',
        padding:30,
    },
    Container: {

        //alignItems:'flex-start',// flex-start 靠在左边显示 center 居中 flex-end 尾部
        //
        flexDirection:'column',//row column 方向
        backgroundColor: '#eae7ff',
        flex: 1,
        //justifyContent:'center',//center ; 居中  flex-end 位于底部  space-between/space-around屏幕平均分配
    },
    Text: {
        color: '#6435c9',
        fontSize: 26,
        textAlign: 'center',
        fontStyle: 'italic',
        letterSpacing: 2,
        lineHeight: 33,
        fontFamily: 'Helvetica Neue',
        fontWeight: '300',
        textDecorationLine: 'underline',
        textDecorationStyle: 'dashed',
    },

});
AppRegistry.registerComponent('Day0718', () => Day0718);

Flex布局是React-Native 中常用的布局语法。