#鸿蒙学习大百科#如何向preference中写入数据？

import ohos.data.preferences.Preferences;
import ohos.data.preferences.PreferencesHelper;
import ohos.app.Context;

// 假设这是在一个 Ability 类中
public class MyFeatureAbility extends Ability {

    @Override
    public void onStart(Intent intent) {
        super.onStart(intent);

        // 获取 Preferences 实例，"my_preferences" 是文件名
        Preferences preferences = PreferencesHelper.getPreferences(getContext(), "my_preferences");

        // 调用方法写入数据
        saveToPreferences(preferences);
    }

    private void saveToPreferences(Preferences preferences) {
        // 获取 Editor 对象
        Preferences.Editor editor = preferences.edit();

        // 向 Preferences 中写入数据
        editor.putString("username", "john_doe");
        editor.putInt("user_age", 30);
        editor.putBoolean("is_premium_user", true);

        // 同步保存数据到存储中
        editor.flushSync();
        // 或者异步保存
        // editor.flush();
    }
}

import dataPreferences from '@ohos.data.preferences';
@Entry
@Component
struct Index {
  build() {
    Column() {
      Button("向preference中写入数据").onClick(() => {
      let preferences =   dataPreferences.getPreferencesSync(getContext(), { name: "myStore" });
        if (preferences.hasSync('name')) {
          console.info("The key 'name' is contained.");
        } else {
          console.info("The key 'name' does not contain.");
          // 此处以此键值对不存在时写入数据为例
          preferences.putSync('name', 'Tom');
          // 当字符串有特殊字符时，需要将字符串转为Uint8Array类型再存储
        }
      })
    }
    .width('100%')
    .height('100%')
    .justifyContent(FlexAlign.Center)
  }

}