React Native 之 Text居中显示

/**
 * Sample React Native App
 * https://github.com/facebook/react-native
 * @flow
 */

import React,{ Component } from 'react';
import {
  AppRegistry,StyleSheet,Image,Text,TouchableHighlight,View
} from 'react-native';

import ImageEqualEnlarge from './ImageEqualEnlarge.js' 

export default class ViewProject extends Component {

  render() {
    return (
      <View style={styles.container}>
         <Text style={styles.textStyle}>
            happy
        </Text>
        <Text style={styles.textStyle}>
            忧伤 
        </Text>
      </View>
    );
  }
}
const styles = StyleSheet.create({
  container: {
    flex:1,justifyContent: 'center',alignItems:'center',}，
  textStyle:{
   height:100,width:200,fontSize:30,backgroundColor:'gray',textAlign:'center',//虽然样式中设置了 justifyContent: 'center'，但无效

   margin:5

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

Text 组件的样式键 textAlign 和 justifyContent 都设置为center，这样字符串应该垂直和水平都居中，但事实上，只会水平居中显示效果如图

正确的做法是 Text组件外边包一层View，且Text组件的样式除了fontSize键值其它样式键值都移到外层View的样式中 如下代码实现：

/**
 * Sample React Native App
 * https://github.com/facebook/react-native
 * @flow
 */

import React,View
} from 'react-native';

import ImageEqualEnlarge from './ImageEqualEnlarge.js' 

export default class ViewProject extends Component {

  render() {
    return (
      <View style={styles.container}>
         <View style={styles.ViewForTextStyle}>
         <Text style={styles.newTextStyle}>
            happy
        </Text>
        </View>
        <View style={styles.ViewForTextStyle}>
        <Text style={styles.newTextStyle}>
            忧伤 
        </Text>
        </View>
      </View>
    );
  }


}



const styles = StyleSheet.create({
  container: {
    flex:1,},newTextStyle:{
   fontSize:30,textStyle:{
   height:100,margin:5
  },ViewForTextStyle:{
    height:100,margin:5
  }

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