HarmonyOS 鸿蒙Next 关于首选项读不了put方法的问题

关于首选项无法读取put方法的问题

按文档 arkui-数据管理-首选项进行测试

直接写在入口ability里面

import hilog from '@ohos.hilog';
import { Ability } from '@ohos.application.Ability'
import { Window } from '@ohos.window'
import data_preferences from '@ohos.data.preferences';
let context = null;
let preferences = null;

export default class EntryAbility extends Ability {
    onCreate(want, launchParam) {
        hilog.isLoggable(0x0000, 'testTag', hilog.LogLevel.INFO);
        hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onCreate');
        hilog.info(0x0000, 'testTag', '%{public}s', 'want param:' + JSON.stringify(want) ?? '');
        hilog.info(0x0000, 'testTag', '%{public}s', 'launchParam:' + JSON.stringify(launchParam) ?? '');

        //初始化首选项
        let promise = data_preferences.getPreferences(this.context,'sdjsdj33');
        promise.then((pref)=>{
            preferences = pref;
        }).catch((err)=>{
            console.info('dataBase init promise catch:' + err);
        })
        //添加数据
        let putPromise = preferences.put('hello','world');
        putPromise.then(()=>{
            console.info('dataBase put promise  succeed:');
        }).catch((err)=>{
            console.info('dataBase put promise catch:' + err);
        })
    }

    onDestroy() {
        hilog.isLoggable(0x0000, 'testTag', hilog.LogLevel.INFO);
        hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onDestroy');
    }

    onWindowStageCreate(windowStage: Window.WindowStage) {
        // Main window is created, set main page for this ability
        hilog.isLoggable(0x0000, 'testTag', hilog.LogLevel.INFO);
        hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onWindowStageCreate');

        windowStage.loadContent('pages/Index', (err, data) => {
            if (err.code) {
                hilog.isLoggable(0x0000, 'testTag', hilog.LogLevel.ERROR);
                hilog.error(0x0000, 'testTag', 'Failed to load the content. Cause: %{public}s', JSON.stringify(err) ?? '');
                return;
            }
            hilog.isLoggable(0x0000, 'testTag', hilog.LogLevel.INFO);
            hilog.info(0x0000, 'testTag', 'Succeeded in loading the content. Data: %{public}s', JSON.stringify(data) ?? '');
        });
        context = this.context;
    }

    onWindowStageDestroy() {
        // Main window is destroyed, release UI related resources
        hilog.isLoggable(0x0000, 'testTag', hilog.LogLevel.INFO);
        hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onWindowStageDestroy');
    }

    onForeground() {
        // Ability has brought to foreground
        hilog.isLoggable(0x0000, 'testTag', hilog.LogLevel.INFO);
        hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onForeground');
    }

    onBackground() {
        // Ability has back to background
        hilog.isLoggable(0x0000, 'testTag', hilog.LogLevel.INFO);
        hilog.info(0x0000, 'testTag', '%{public}s', 'Ability onBackground');
    }
}

然后就报了一个错误

这是原log，我实在时搞不懂，首选项的文档里面说的明明白白,api 9 he stage模式适用，难度我这不是？模拟器是远程的p50，写的清清楚楚api 9啊。。。。，新建项目选的也是api 9和stage啊。。。兄弟们救救我。

Device info:OpenHarmony 2.0 Canary
Build info:OpenHarmony 3.2.6.3
Module name:com.brejce.managermony
Version:1.0.0
Pid:1201
Uid:20040003
Reason:TypeError
Error message:Cannot read property put of null
Stacktrace:
Cannot get SourceMap info, dump raw stack: