javascript - React Native 数据不会在第一次点击时推送到 firebase

Question

我正在尝试将 TextInput 字段中的数据和创建的时间戳都推送到 Firebase 实时数据库。然而，当应用程序加载时，第一次点击提交只会提交文本输入而不是“时间戳”

这是一个简单版本的文件，

import React, { Component } from 'react';  
import { View, Text, TouchableHighlight, StyleSheet, 
ImageBackground, TextInput, Alert, Picker, TouchableWithoutFeedback, 
Keyboard } from 'react-native';

import React, { Component } from 'react';  
import { View, Text, TouchableHighlight, StyleSheet, 
ImageBackground, TextInput, Alert, Picker, TouchableWithoutFeedback, 
Keyboard } from 'react-native';

import { db } from '../config';


let date = new Date().getDate(); //Current Date

let month = new Date().getMonth() + 1; //Current Month

let year = new Date().getFullYear(); //Current Year

let hours = new Date().getHours(); //Current Hours

let min = new Date().getMinutes(); //Current Minutes

let sec = new Date().getSeconds(); //Current Seconds

let currentTimeAndDate


const updateDatabase = item => {
  db.ref('/Database/...').push({
    Amount: item,
    time: currentTimeAndDate
  });
};

export default class AddItem extends Component {  

constructor(props) {
  super (props);

  this.state = {
    pickerSelection: "default value!",
    date: " "

  };
}


handleSubmit = () => {    

  this.setState({
    //Setting the value of the date time
    date:
      date + '/' + month + '/' + year + ' ' + hours + ':' + min + 
':' + sec,

  });

  currentTimeAndDate = this.state.date

if (this.state.pickerSelection === "WHATEVER") {
      updateDatabase(this.state.textInputField);
      Alert.alert("database updated!");


//This is a short version of the View:

render() {
    return (

 <View>
  <TouchableHighlight
    onPress={TextInput.CheckTextInputIsEmptyOrNot}
    onPress={this.handleSubmit} 
   >
    <Text style={styles.buttonText}>Update</Text>
    </TouchableHighlight>
 </View>

 );
}

我已经尝试在单击 TouchableHighLight 时在文本中显示 currentTimeAndDate。它不会显示加载应用后第一次点击，但会显示第二次。

在 firebase 中，第一次点击时数据是这样输入的:

EJDPvodisjpINJI_9
   amount: "(input number fx. 10)"
   time:   " "

第二次点击:

Efvpspodvpoep_10
   amount: "(input number fx. "10")"
   time:   "(the local time of click fx. "8/5/2019 19:28:28")"

如何让它第一时间发送本地时间？

Answer 1

如何简单地将 currentDateTime 传递到您的 updateDatabase 调用中？

所以你会这样调用它:

updateDatabase(this.state.textInputField, currentTimeAndDate);

然后函数本身是:

const updateDatabase = (item, time) => {
  db.ref('/Database/...').push({
    Amount: item,
    time: time
  });
};