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

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initPreferen