反应本机中的卡视图显示空白的白色屏幕

Question

我想显示这样的卡片，但屏幕变黑，如何在React Native应用中显示卡片视图？

https://react-native-elements.github.io/react-native-elements/docs/card.html，

我的App.js文件的代码

const users = [
  {
     name: 'brynn',
     avatar: 'https://s3.amazonaws.com/uifaces/faces/twitter/brynn/128.jpg'
  }
 ]

 const styles = StyleSheet.create({
  container: {
     flex: 1,
     justifyContent: "center",
     alignItems: "center"
    }
  })

 import {StyleSheet, View, Text, Image } from 'react-native'
 import { Card, ListItem, Button, Icon } from 'react-native-elements'





<Card title="CARD WITH DIVIDER">
  {
    users.map((u, i) => {
      return (
        <View key={i} style={styles.user}>
          <Image
            style={styles.image}
            resizeMode="cover"
            source={{ uri: u.avatar }}
          />
          <Text style={styles.name}>{u.name}</Text>
        </View>
      );
    })
  }
</Card>

import * as React from 'react';