将新值放入输入字段时，会擦除前一个值

Question

使用我当前的代码，我有两个输入字段和一个下拉菜单。当将值放入字段或修改时，它会清除其余字段。唯一保持一致的是下拉菜单。我怀疑我的useEffect钩子可能正在做某事，但我不确定为什么。任何建议都会很棒。 (仅供参考：storeArtic是Firebase的推动力(

自定义屏幕.js

import React, { useState } from "react";
import { StyleSheet, Text, Keyboard, View, TouchableWithoutFeedback } from "react-native";
import { Button, Input } from "react-native-elements";
import { Dropdown } from "react-native-material-dropdown";
import { storeArtic } from '../helpers/fb-settings';
const CustomScreen = ({ route, navigation }) =>{
//create a screen with the ability to add a picture with text to the deck of artic cards
//add check box solution for selection of word type (maybe bubbles, ask about this)
const articDrop = [
{value: 'CV'},
{value: 'VC'},
{value: 'VV'},
{value: 'VCV'},
{value: 'CVCV'},
{value: 'C1V1C1V2'},
{value: 'C1V1C2V2'},
];
const [articCard, setCard] = useState({
word: '',
imageUrl: '',
aType:'',
cType: '',
mastery: false
})
return(
<TouchableWithoutFeedback onPress={Keyboard.dismiss}>
<View>
<Text>Please enter the information of your custom card!</Text>
<Input
placeholder="Enter valid image url"
value={articCard.imageUrl}
autoCorrect={false}
onChangeText={(val) => setCard({ imageUrl: val })}
/>        
<Input
placeholder="Enter word or phrase"
value={articCard.word}
autoCorrect={false}
onChangeText={(val) => 
setCard({ word: val, aType: val.charAt(0).toUpperCase(), mastery: false})
}
/>
<Dropdown
value={articCard.cType}
onChangeText={(text) => setCard({cType: text})}
label="Artic Type"
data={articDrop}
/>
<Button
//this will save the cards to the database
title="Save"
onPress={() => {
storeArtic({articCard})
}} 
/>
<Button
title="Clear"
onPress={() => {
setCard({word: '', aType: '', cType: '', imageUrl: '', mastery: false});
navigation.navigate('Home');
}}
/>
</View>
</TouchableWithoutFeedback>
)
}

export default CustomScreen;

主屏幕.js

import React, { useState, useEffect } from "react";
import { StyleSheet, Text, Keyboard, TouchableOpacity, View, TouchableWithoutFeedback, Image } from "react-native";
import { Button } from "react-native-elements";
import { Feather } from "@expo/vector-icons";
import { initArticDB, setupArticListener } from '../helpers/fb-settings';

const HomeScreen = ({route, navigation}) => {
const [ initialDeck, setInitialDeck] = useState([]);
useEffect(() => {
try {
initArticDB();
} catch (err) {
console.log(err);
}
setupArticListener((items) => {
setInitialDeck(items);
});
}, []);
useEffect(() => {
if(route.params?.articCard){
setCard({imageUrl: state.imageUrl, word: state.word, aType: state.aType, cType: state.cType, mastery: state.mastery})
}
}, [route.params?.articType] );

navigation.setOptions({
headerRight: () => (
<TouchableOpacity
onPress={() =>
navigation.navigate('Settings')
}
>
<Feather
style={styles.headerButton}
name="settings"
size={24}
color="#fff"
/>
</TouchableOpacity>
),
headerLeft: () => (
<TouchableOpacity
onPress={() =>
navigation.navigate('About')
}
>
<Text style={styles.headerButton}> About </Text>
</TouchableOpacity>
),
});
return(
<TouchableWithoutFeedback onPress={Keyboard.dismiss}>
<View style={styles.container}>
<Text style={styles.textmenu}>Welcome to Artic Cards</Text>
<Text style={styles.textsubmenu}>Press Start to Begin!</Text>
<Image source={require('../assets/5-snowflake-png-image.png')}
style={{width: 300, height: 300, alignSelf: 'center'}}/>
<Button
title="Start"
style={styles.buttons}
onPress={() => navigation.navigate('Cards',
{passDeck: initialDeck})}
/>
<Button
title="Progress"
style={styles.buttons}
onPress={() => navigation.navigate('Progress')}
/>
<Button
title="Customize"
style={styles.buttons}
onPress={() => navigation.navigate('Customize')}
/>
</View>
</TouchableWithoutFeedback>
);
};
const styles = StyleSheet.create({
container: {
padding: 10,
backgroundColor: '#E8EAF6',
flex: 1,
justifyContent: 'center'
},
textmenu: {
textAlign: 'center',
fontSize: 30
},
textsubmenu:{
textAlign: 'center',
fontSize: 15
},
headerButton: {
color: '#fff',
fontWeight: 'bold',
margin: 10,
},
buttons: {
padding: 10,
},
inputError: {
color: 'red',
},
input: {
padding: 10,
},
resultsGrid: {
borderColor: '#000',
borderWidth: 1,
},
resultsRow: {
flexDirection: 'row',
borderColor: '#000',
borderBottomWidth: 1,
},
resultsLabelContainer: {
borderRightWidth: 1,
borderRightColor: '#000',
flex: 1,
},
resultsLabelText: {
fontWeight: 'bold',
fontSize: 20,
padding: 10,
},
resultsValueText: {
fontWeight: 'bold',
fontSize: 20,
flex: 1,
padding: 10,
},
});
export default HomeScreen;

Answer 1

与基于类的setState不同，当您执行setState时，使用功能组件，它将使用您在setState函数中提供的内容覆盖状态。我们有责任修改国家(而不是过度(

因此，如果您的状态是一个对象，请使用回调方法并传播以前的状态，然后更新新状态。

喜欢这个

<Input
placeholder="Enter valid image url"
value={articCard.imageUrl}
autoCorrect={false}
onChangeText={(val) => setCard(prev => ({ ...prev, imageUrl: val }))} //<----- like this
/> 

对所有输入执行相同的操作。