# 后台代理提醒开发指导

## 场景介绍

后台代理提醒主要提供后台提醒发布接口，开发者在应用开发时，可以调用这些接口去创建定时提醒，包括倒计时、日历、闹钟三种提醒类型。使用后台代理提醒能力后，应用可以被冻结或退出，计时和弹出提醒的功能将被后台系统服务代理。


## 接口说明

reminderAgent：封装了发布、取消提醒类通知的方法。

具体后台提醒相关功能接口请见[后台代理提醒](../reference/apis/js-apis-reminderAgent.md)。

**表1** reminderAgent主要接口

| 接口名 | 描述 |
| -------- | -------- |
| publishReminder(reminderReq:&nbsp;ReminderRequest,&nbsp;callback:&nbsp;AsyncCallback&lt;number&gt;):&nbsp;void<br/>publishReminder(reminderReq:&nbsp;ReminderRequest):&nbsp;Promise&lt;number&gt; | 发布一个定时提醒类通知。<br/>单个应用有效的提醒个数最多支持30个（不包括已经超时，即后续不会再提醒的提醒实例）<br/>整个系统有效的提醒个数最多支持2000个（不包括已经超时，即后续不会再提醒的提醒实例） |
| cancelReminder(reminderId:&nbsp;number,&nbsp;callback:&nbsp;AsyncCallback&lt;void&gt;):&nbsp;void<br/>cancelReminder(reminderId:&nbsp;number):&nbsp;Promise&lt;void&gt; | 取消一个指定的提醒类通知。(reminderId从publishReminder的返回值获取) |
| getValidReminders(callback:&nbsp;AsyncCallback&lt;Array&lt;ReminderRequest&gt;&gt;):&nbsp;void<br/>getValidReminders():&nbsp;Promise&lt;Array&lt;ReminderRequest&gt;&gt; | 获取当前应用设置的所有有效的提醒。 |
| cancelAllReminders(callback:&nbsp;AsyncCallback&lt;void&gt;):&nbsp;void<br/>cancelAllReminders():&nbsp;Promise&lt;void&gt; | 取消当前应用设置的所有提醒 |
| addNotificationSlot(slot:&nbsp;NotificationSlot,&nbsp;callback:&nbsp;AsyncCallback&lt;void&gt;):&nbsp;void<br/>addNotificationSlot(slot:&nbsp;NotificationSlot):&nbsp;Promise&lt;void&gt; | 注册一个提醒类需要使用的NotificationSlot |
| removeNotificationSlot(slotType:&nbsp;notification.SlotType,&nbsp;callback:&nbsp;AsyncCallback&lt;void&gt;):&nbsp;void<br/>removeNotificationSlot(slotType:&nbsp;notification.SlotType):&nbsp;Promise&lt;void&gt; | 删除指定类型的NotificationSlot |

## 开发步骤

> ![icon-note.gif](public_sys-resources/icon-note.gif) **说明：**
>
> 1. 应用需要配置权限：ohos.permission.PUBLISH_AGENT_REMINDER。
>
> 2. 应用需要申请通知弹窗：[Notification.requestEnableNotification](../reference/apis/js-apis-notification.md#notificationrequestenablenotification8)。

1. 定义一个提醒代理。

   倒计时实例定义：
   ```js
   import reminderAgent from '@ohos.reminderAgent';
   import notification from '@ohos.notification';
   export default {
       // eTS工程：
       let timer : reminderAgent.ReminderRequestTimer = {
           reminderType: reminderAgent.ReminderType.REMINDER_TYPE_TIMER,
           triggerTimeInSeconds: 10,
           actionButton: [
               {
                   title: "close",
                   type: reminderAgent.ActionButtonType.ACTION_BUTTON_TYPE_CLOSE
               }
           ],
           wantAgent: {
               pkgName: "com.example.device",
               abilityName: "com.example.device.MainAbility"
           },
           maxScreenWantAgent: {
               pkgName: "com.example.device",
               abilityName: "com.example.device.MainAbility"
           },
           title: "this is title",
           content: "this is content",
           expiredContent: "this reminder has expired",
           notificationId: 100,
           slotType: notification.SlotType.SOCIAL_COMMUNICATION
       }
   }
   ```

   日历实例定义：

    ```js
    // eTS工程：
    let calendar : reminderAgent.ReminderRequestCalendar = {
        reminderType: reminderAgent.ReminderType.REMINDER_TYPE_CALENDAR,
        dateTime: {
            year: 2050,
            month: 7,
            day: 30,
            hour: 11,
            minute: 14,
            second: 30
        },
        repeatMonths: [1],
        repeatDays: [1],
        actionButton: [
            {
                title: "close",
                type: reminderAgent.ActionButtonType.ACTION_BUTTON_TYPE_CLOSE
            },
            {
                title: "snooze",
                type: reminderAgent.ActionButtonType.ACTION_BUTTON_TYPE_SNOOZE
            },
        ],
        wantAgent: {
            pkgName: "com.example.device",
            abilityName: "com.example.device.MainAbility"
        },
        maxScreenWantAgent: {
            pkgName: "com.example.device",
            abilityName: "com.example.device.MainAbility"
        },
        ringDuration: 5,
        snoozeTimes: 2,
        timeInterval: 5,
        title: "this is title",
        content: "this is content",
        expiredContent: "this reminder has expired",
        snoozeContent: "remind later",
        notificationId: 100,
        slotType: notification.SlotType.SOCIAL_COMMUNICATION
    }
    ```

    闹钟实例定义：

    ```js
    // eTS工程：
    let alarm : reminderAgent.ReminderRequestAlarm = {
        reminderType: reminderAgent.ReminderType.REMINDER_TYPE_ALARM,
        hour: 11,
        minute: 14,
        daysOfWeek: [0],
        actionButton: [
            {
                title: "close",
                type: reminderAgent.ActionButtonType.ACTION_BUTTON_TYPE_CLOSE
            },
            {
                title: "snooze",
                type: reminderAgent.ActionButtonType.ACTION_BUTTON_TYPE_SNOOZE
            },
        ],
        wantAgent: {
            pkgName: "com.example.device",
            abilityName: "com.example.device.MainAbility"
        },
        maxScreenWantAgent: {
            pkgName: "com.example.device",
            abilityName: "com.example.device.MainAbility"
        },
        ringDuration: 5,
        snoozeTimes: 2,
        timeInterval: 5,
        title: "this is title",
        content: "this is content",
        expiredContent: "this reminder has expired",
        snoozeContent: "remind later",
        notificationId: 100,
        slotType: notification.SlotType.SOCIAL_COMMUNICATION
    }
    ```

2. 发布倒计时提醒。
   ```js
   startTimer() {
       reminderAgent.publishReminder(this.timer, (err, reminderId) =>{
           this.printInfo(JSON.stringify(err));
           this.printInfo("reminderId:" + reminderId);
       });
   }
   ```

   HML页面：
   ```html
   <div class="container">
       <button type="text" value="publishReminder" onclick="startTimer"></button>
   </div>
   ```

## 相关实例

基于后台代理提醒开发，有以下相关实例可供参考：

- [`AlarmClock`：后台代理提醒（eTS）（API8）](https://gitee.com/openharmony/applications_app_samples/tree/samples_monthly_0730/Notification/AlarmClock)

- [`FlipClock`：翻页时钟（eTS）（API8）（Full SDK）](https://gitee.com/openharmony/applications_app_samples/tree/samples_monthly_0730/CompleteApps/FlipClock)