آموزش بعدی توسعه Hongmeng: یک خط کد برای اجرای ذخیره سازی داده ها

try {
    dataPreferences.getPreferences(getContext(this),'DB_NAME',(err, preferences) => {
      preferences.put('name','bob',(err)=>{
        if (err) {
          console.error(`Failed to put data. Code:${err.code}, message:${err.message}`);
          return;
        }
        preferences.flush()
        console.info('Succeeded in putting data.');
      })
    })
}catch (err){
}

try {
    dataPreferences.getPreferences(getContext(this),'DB_NAME',(err, preferences) => {
      preferences.put('name','bob',(err)=>{
        if (err) {
          console.error(`Failed to put data. Code:${err.code}, message:${err.message}`);
          return;
        }
        preferences.flush()
        console.info('Succeeded in putting data.');
      })
    })
}catch (err){
}

async putData( key: string,data: string,db_name: string = defaultPreferenceName) {
    if (!preference) {
      await this.getPreferencesFromStorage(db_name);
    }
    try {
        await preference.put(key, data);
    } catch (err) {
    }
    await preference.flush();
  }

async getData( key: string,db_name: string = defaultPreferenceName) {
    if (!preference) {
      await this.getPreferencesFromStorage(db_name);
    }
    return await preference.get(key, '')
  }

PreferenceModel.putData('name','bob')

let name = await PreferenceModel.getData('name')

import dataPreferences from '@ohos.data.preferences';

let context = getContext(this);
let preference: dataPreferences.Preferences;
let preferenceTemp: dataPreferences.Preferences;
const defaultPreferenceName: string = "DB_NAME"

class PreferenceModel {
  async getPreferencesFromStorage(db_name: string) {
    try {
      preference = await dataPreferences.getPreferences(context, db_name);
    } catch (err) {
    }
  }

  /**
   * 删除
   */
  async deleteLocalPreferences(key) {
    try {
      await dataPreferences.deletePreferences(context,key);
    } catch(err) {
    };
    preference = preferenceTemp;
  }

  /**
   * 存储
   */
  async putData( key: string,data: string,db_name: string = defaultPreferenceName) {
    if (!preference) {
      await this.getPreferencesFromStorage(db_name);
    }
    try {
        await preference.put(key, data);
    } catch (err) {
    }
    await preference.flush();
  }

  /**
   * 取数据
   */
  async getData( key: string,db_name: string = defaultPreferenceName) {
    if (!preference) {
      await this.getPreferencesFromStorage(db_name);
    }
    return await preference.get(key, '')
  }
}

export default new PreferenceModel();