OpenHarmony 快速集成轻量级存储（dataPreferences）工具类

OpenHarmony中也有类似于Android的SharedPreferences的轻量级存储，名字叫dataPreferences，这里省略介绍，直接放工具类

一.初始化

首先在EntryAbility中对dataPreferences进行初始化操作，初始化的代码如下：

import dataPreferences from '@ohos.data.preferences';export var preferences: dataPreferences.Preferences | null = null;/*** 获取preferences实例*/initPreferenceData() {try {dataPreferences.getPreferences(this.context, 'mystore', function (err, val) {if (err) {console.error("Failed to get preferences. code =" + err.code + ", message =" + err.message);return;}preferences = val;console.info("Succeeded in getting preferences.");})} catch (err) {console.error("Failed to get preferences. code =" + err.code + ", message =" + err.message);}}

将上述的initPreferenceData方法在onWindowStageCreate中进行调用

二.工具类

然后新建工具类拷贝如下代码

import { preferences } from '../entryability/EntryAbility';
import Logger from './Logger';const TAG: string = '[PreferencesDataUtils]'export const KEY_SN: string = "KEY_SN"type ValueType = number | string | boolean | Array<number> | Array<string> | Array<boolean>export function getPreferencesData(key: string,valueCallBack:(value:ValueType) => void, defaultValue: string = '') {try {preferences.get(key, defaultValue, (err, val) => {if (err) {Logger.error(TAG, `Failed to get value of 'startup'. Code:${err.code}, message:${err.message}`);valueCallBack("")return;}Logger.info(TAG, `Succeeded in getting value of 'startup'. val: ${val}.`);valueCallBack(val)})} catch (err) {Logger.error(TAG, `Failed to get value of 'startup'. Code:${err.code}, message:${err.message}`);valueCallBack("")}
}export function putPreferencesData(key: string, value: ValueType) {preferences.put(key, value, (err) => {if (err) {Logger.error(TAG, `Failed to put ${key} data. Code:${err.code}, message:${err.message}`);return;}Logger.info(TAG, `Succeeded in putting ${key} data ${value}.`);try {preferences.flush(function (err) {if (err) {Logger.error(TAG, "Failed to flush. code =" + err.code + ", message =" + err.message);return;}Logger.info(TAG, "Succeeded in flushing.");})} catch (err) {Logger.error(TAG, "Failed to flush. code =" + err.code + ", message =" + err.message);}})
}

防止报错我这一并吧Logger工具类放在下面了

import hilog from '@ohos.hilog'class Logger {private domain: numberprivate prefix: stringprivate format: string = "%{public}s, %{public}s"constructor(prefix: string) {this.prefix = prefixthis.domain = 0xFF00}debug(...args: string[]) {hilog.debug(this.domain, this.prefix, this.format, args)}info(...args: string[]) {hilog.info(this.domain, this.prefix, this.format, args)}warn(...args: string[]) {hilog.warn(this.domain, this.prefix, this.format, args)}error(...args: string[]) {hilog.error(this.domain, this.prefix, this.format, args)}
}export default new Logger('[FCT]')