【发布时间】:2019-11-30 10:15:29
【问题描述】:
我不知道这是否可能,但我正在尝试将持久数据存储在异步存储中,因此每当获取存储键中的数组数据时,该持久数据始终位于数组的顶部。此外,无法删除持久数据。下面是一个示例代码,为了更清楚,我只展示了函数。
componentWillMount() {
this.saveData();
}
componentDidMount() {
this.getDataSync();
}
getDataSync = async () => {
try {
const list = await AsyncStorage.getItem(LIST_STORAGE_KEY);
const parsedList = JSON.parse(list);
this.setState({
isDataReady: true,
list: parsedList || []
});
console.log(parsedList, this.state.list);
} catch (e) {
Alert.alert('Failed to load list.');
}
}
saveData = () => {
const data = [
{
firstname: 'John',
lastname: 'Doe',
image: null,
email: 'john@doe.com',
key: 0,
phone: '19191919191',
},
];
this.setState(
prevState => ({
list: [data, ...prevState.list]
}),
() => this.saveItems(this.state.list)
);
}
handleDelete(item) {
if (item.key === 0) {
Alert.alert('You cannot delete this user');
} else {
this.setState(({ list }) => ({
list: list.filter(o => o.key !== item.key)
}),
() => this.saveItems(this.state.list)
);
console.log('deleted: ', item);
}
}
handleAdd() {
const { firstname, lastname, email, phone } = this.state;
const ID = uuid();
const newItemObject = {
key: ID,
firstname: firstname,
lastname: lastname,
email: email,
phone: phone,
image: null,
};
this.setState(
prevState => ({
list: [...prevState.list, newItemObject]
}),
() => this.saveItems(this.state.list)
);
}
saveItems = list => {
AsyncStorage.setItem(LIST_STORAGE_KEY, JSON.stringify(list));
};
【问题讨论】:
-
这是对象列表还是字符串列表?
-
它是一个对象列表
标签: javascript arrays reactjs react-native asyncstorage