根据卡片状态刷新不同内容
相同的卡片可以添加到桌面上实现不同的功能，比如添加两张桌面的卡片，一张显示杭州的天气，一张显示北京的天气，设置每天早上7点触发定时刷新，卡片需要感知当前的配置是杭州还是北京，然后将对应城市的天气信息刷新到卡片上，以下示例介绍了如何根据卡片的状态动态选择需要刷新的内容。
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卡片配置文件：配置每隔30分钟自动刷新。
{"forms": [{"name": "WidgetUpdateByStatus","description": "$string:UpdateByStatusFormAbility_desc","src": "./ets/widgetupdatebystatus/pages/WidgetUpdateByStatusCard.ets","uiSyntax": "arkts","window": {"designWidth": 720,"autoDesignWidth": true},"isDefault": true,"updateEnabled": true,"scheduledUpdateTime": "10:30","updateDuration": 1,"defaultDimension": "2*2","supportDimensions": ["2*2"]}]} -
卡片页面：卡片具备不同的状态选择，在不同的状态下需要刷新不同的内容，因此在状态发生变化时通过postCardAction通知EntryFormAbility。
// entry/src/main/ets/widgetupdatebystatus/pages/WidgetUpdateByStatusCard.etslet storageUpdateByStatus = new LocalStorage();@Entry(storageUpdateByStatus)@Componentstruct WidgetUpdateByStatusCard {// $r('app.string.to_be_refreshed')需要替换为开发者所需的资源文件@LocalStorageProp('textA') textA: Resource = $r('app.string.to_be_refreshed');@LocalStorageProp('textB') textB: Resource = $r('app.string.to_be_refreshed');@State selectA: boolean = false;@State selectB: boolean = false;build() {Column() {Column() {Row() {Checkbox({ name: 'checkbox1', group: 'checkboxGroup' }).padding(0).select(false).margin({ left: 26 }).onChange((value: boolean) => {this.selectA = value;postCardAction(this, {action: 'message',params: {selectA: JSON.stringify(value)}});})// $r('app.string.status_a')需要替换为开发者所需的资源文件Text($r('app.string.status_a')).fontColor('#000000').opacity(0.9).fontSize(14).margin({ left: 8 })}.width('100%').padding(0).justifyContent(FlexAlign.Start)Row() {Checkbox({ name: 'checkbox2', group: 'checkboxGroup' }).padding(0).select(false).margin({ left: 26 }).onChange((value: boolean) => {this.selectB = value;postCardAction(this, {action: 'message',params: {selectB: JSON.stringify(value)}});})// $r('app.string.status_b')需要替换为开发者所需的资源文件Text($r('app.string.status_b')).fontColor('#000000').opacity(0.9).fontSize(14).margin({ left: 8 })}.width('100%').position({ y: 32 }).padding(0).justifyContent(FlexAlign.Start)}.position({ y: 12 })Column() {Row() {// 选中状态A才会进行刷新的内容Text($r('app.string.status_a')).fontColor('#000000').opacity(0.4).fontSize(12)Text(this.textA).fontColor('#000000').opacity(0.4).fontSize(12)}.margin({ top: '12px', left: 26, right: '26px' })Row() {// 选中状态B才会进行刷新的内容Text($r('app.string.status_b')).fontColor('#000000').opacity(0.4).fontSize(12)Text(this.textB).fontColor('#000000').opacity(0.4).fontSize(12)}.margin({top: '12px',bottom: '21px',left: 26,right: '26px'})}.margin({ top: 80 }).width('100%').alignItems(HorizontalAlign.Start)}.width('100%').height('100%')// $r('app.media.CardUpdateByStatus')需要替换为开发者所需的资源文件.backgroundImage($r('app.media.CardUpdateByStatus')).backgroundImageSize(ImageSize.Cover)}} -
EntryFormAbility：将卡片的状态存储在本地数据库中，在刷新事件回调触发时，通过formId获取当前卡片的状态，然后根据卡片的状态选择不同的刷新内容。
// entry/src/main/ets/updatebystatusformability/UpdateByStatusFormAbility.tsimport { Want } from '@kit.AbilityKit';import { preferences } from '@kit.ArkData';import { BusinessError } from '@kit.BasicServicesKit';import { formBindingData, FormExtensionAbility, formInfo, formProvider } from '@kit.FormKit';import { hilog } from '@kit.PerformanceAnalysisKit';const TAG: string = 'UpdateByStatusFormAbility';const DOMAIN_NUMBER: number = 0xFF00;export default class UpdateByStatusFormAbility extends FormExtensionAbility {onAddForm(want: Want): formBindingData.FormBindingData {let formId: string = '';if (want.parameters) {formId = want.parameters[formInfo.FormParam.IDENTITY_KEY].toString();let promise: Promise<preferences.Preferences> = preferences.getPreferences(this.context, 'myStore');promise.then(async (storeDB: preferences.Preferences) => {hilog.info(DOMAIN_NUMBER, TAG, 'Succeeded to get preferences.');await storeDB.put('A' + formId, 'false');await storeDB.put('B' + formId, 'false');await storeDB.flush();}).catch((err: BusinessError) => {hilog.info(DOMAIN_NUMBER, TAG, `Failed to get preferences. ${JSON.stringify(err)}`);});}let formData: Record<string, Object | string> = {};return formBindingData.createFormBindingData(formData);}onRemoveForm(formId: string): void {hilog.info(DOMAIN_NUMBER, TAG, 'onRemoveForm, formId:' + formId);let promise = preferences.getPreferences(this.context, 'myStore');promise.then(async (storeDB) => {hilog.info(DOMAIN_NUMBER, TAG, 'Succeeded to get preferences.');await storeDB.delete('A' + formId);await storeDB.delete('B' + formId);}).catch((err: BusinessError) => {hilog.info(DOMAIN_NUMBER, TAG, `Failed to get preferences. ${JSON.stringify(err)}`);});}// 当前卡片使用方不会涉及该场景，无需实现该回调函数onCastToNormalForm(formId: string): void {}onUpdateForm(formId: string): void {let promise: Promise<preferences.Preferences> = preferences.getPreferences(this.context, 'myStore');promise.then(async (storeDB: preferences.Preferences) => {hilog.info(DOMAIN_NUMBER, TAG, 'Succeeded to get preferences from onUpdateForm.');let stateA = await storeDB.get('A' + formId, 'false');let stateB = await storeDB.get('B' + formId, 'false');// A状态选中则更新textAif (stateA === 'true') {let param: Record<string, string> = {'textA': 'AAA'};let formInfo: formBindingData.FormBindingData = formBindingData.createFormBindingData(param);await formProvider.updateForm(formId, formInfo);}// B状态选中则更新textBif (stateB === 'true') {let param: Record<string, string> = {'textB': 'BBB'};let formInfo: formBindingData.FormBindingData = formBindingData.createFormBindingData(param);await formProvider.updateForm(formId, formInfo);}hilog.info(DOMAIN_NUMBER, TAG, `Update form success stateA:${stateA} stateB:${stateB}.`);}).catch((err: BusinessError) => {hilog.info(DOMAIN_NUMBER, TAG, `Failed to get preferences. ${JSON.stringify(err)}`);});}onFormEvent(formId: string, message: string): void {// 存放卡片状态hilog.info(DOMAIN_NUMBER, TAG, 'onFormEvent formId:' + formId + 'msg:' + message);let promise: Promise<preferences.Preferences> = preferences.getPreferences(this.context, 'myStore');promise.then(async (storeDB: preferences.Preferences) => {hilog.info(DOMAIN_NUMBER, TAG, 'Succeeded to get preferences.');let msg: Record<string, string> = JSON.parse(message);if (msg.selectA !== undefined) {hilog.info(DOMAIN_NUMBER, TAG, 'onFormEvent selectA info:' + msg.selectA);await storeDB.put('A' + formId, msg.selectA);}if (msg.selectB !== undefined) {hilog.info(DOMAIN_NUMBER, TAG, 'onFormEvent selectB info:' + msg.selectB);await storeDB.put('B' + formId, msg.selectB);}await storeDB.flush();}).catch((err: BusinessError) => {hilog.info(DOMAIN_NUMBER, TAG, `Failed to get preferences. ${JSON.stringify(err)}`);});}}
通过本地数据库进行卡片信息的持久化时，建议先在onAddForm生命周期进行卡片信息持久化；同时需要在卡片销毁(onRemoveForm)时删除当前卡片存储的持久化信息，避免反复添加删除卡片导致数据库文件持续变大。