AsyncStorage React Native 保存一个数组
我尝试保存一个数组,我尝试按照文档进行操作,但失败了.应该怎么写才不会给我各种警告和错误.
I tried saving an array, I tried to follow the documentation but failed miserably. How should I write it so that it doesn't give me various warnings and errors.
错误:
- 当我尝试设置项目时得到一个 [Object Object]
- 得到一个对象而不是数组
- 试图分配给只读属性
- 需要一个字符串,得到一个数组
这里是代码:App.js
import React from "react";
import {
StyleSheet,
Text,
View,
TextInput,
ScrollView,
TouchableOpacity,
KeyboardAvoidingView,
AsyncStorage
} from "react-native";
import Note from "./app/components/note";
export default class App extends React.Component {
state = {
noteArray: [],
noteText: ""
};
render() {
let notes = this.state.noteArray.map((val, key) => {
return (
<Note
key={key}
keyval={key}
val={val}
deleteMethod={() => this.deleteNote(key)}
/>
);
});
return (
<KeyboardAvoidingView behavior="padding" style={styles.container}>
<View style={styles.header}>
<Text style={styles.headerText}>Tasker</Text>
</View>
<ScrollView style={styles.scrollContainer}>{notes}</ScrollView>
<View style={styles.footer}>
<TouchableOpacity
onPress={this.addNote.bind(this)}
style={styles.addButton}
>
<Text style={styles.addButtonText}>+</Text>
</TouchableOpacity>
<TextInput
style={styles.textInput}
placeholder="Enter Task..."
placeholderTextColor="white"
underlinedColorAndroid="transparent"
onChangeText={noteText => this.setState({ noteText })}
value={this.state.noteText}
/>
</View>
</KeyboardAvoidingView>
);
}
addNote() {
if (this.state.noteText) {
var d = new Date();
this.state.noteArray.push({
date:
d.getFullYear() +
"/" +
(d.getMonth() + 1) +
"/" +
d.getDate(),
note: this.state.noteText
});
this.setState({ noteArray: this.state.noteArray });
this.setState({ noteText: "" });
}
//AsyncStorage.setItem() How do I write it so no errors occur
alert({ noteArray: this.state.noteArray });
}
}
额外说明:错误出现在我的 Android 和 iOS 手机上的 Expo App 上
Extra Note : The Error is on Expo App on my phone both Android and iOS
提前致谢!
推荐答案
数组和其他对象需要在AsyncStorage中保存为字符串.
Arrays and other objects need to be saved as strings in AsyncStorage.
AsyncStorage.setItem('arrayObjKey', JSON.stringify(myArray));
如果您需要更新数组中的值,请使用 AsyncStorage.multiMerge
Also if you need to update the values in the array use AsyncStorage.multiMerge
来自 React-Native 文档:
From the React-Native docs:
将现有键值与输入值合并,假设两个值都是字符串化的 JSON.返回一个 Promise 对象.
Merges an existing key value with an input value, assuming both values are stringified JSON. Returns a Promise object.
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