在本机运行遇到此问题的情况下创建应用程序.基本上,我应该创建一个页面,以打印当前登录到数据库(firebase)的用户的数据.我设法创建了一种排行榜,可以在所有页面上用数据打印所有用户,但是我无法弄清楚哪里出了问题.有人能帮我吗？

https://snack.expo.io/@khal_d/proj-p-3

import React,{ Component } from 'react';
import { View,TouchableOpacity,StyleSheet,Button,Text,ScrollView,ListItem } from 'react-native';
import { Input,Card} from 'react-native-elements';

import * as firebase from 'firebase';


export default class User extends Component {
   static navigationOptions = {
    title: 'UserInfo',};

  state = {
    data: [],};

  // Controllare qui
  componentDidMount(){
    //leggere array dal db
    const currentUID = firebase.auth().currentUser.uid;
    const path ="/users/" + currentUID;
    const users = firebase.database().ref(path);
    users.on("value",snap => {
      console.log("log di snap" + snap);
      //ciclo
      var elenco = [];
      snap.forEach(child => {
        elenco.push({
          name: child.val().name,surname: child.val().surname,email: child.val().email,image: child.val().image,})
      });

      console.log("altro log finale" + elenco);
      this.setState({data:elenco})
    });

  }

// controllare fino a qua

  render() {

    return (
      <ScrollView>
      <View>
        <Card> //fix evertything all'interno di card
          {
    this.state.data.map((l,i) => (
      <ListItem
        key={i}
        leftAvatar={{ source: { uri: l.image } }}
        title={l.name}
        subtitle={l.surname}

      />
    ))
  }
        </Card>
      </View>
      </ScrollView>
    );
  }
}