HarmonyOS基础技术赋能之通知功能实现 原创 精华

引言
HarmonyOS通过ANS（Advanced Notification Service，即通知增强服务）系统服务来为应用程序提供发布通知的能力。通知提供应用的即时消息或通信消息，用户可以直接删除或点击通知触发进一步的操作。

功能介绍
HarmonyOS提供了通知功能，即在一个应用的UI界面之外显示的消息，主要用来提醒用户有来自该应用中的信息。当应用向系统发出通知时，它将先以图标的形式显示在通知栏中，用户可以下拉通知栏查看通知的详细信息。常见的使用场景：

1) 显示接收到短消息、即时消息等。

2) 显示应用的推送消息，如广告、版本更新等。

3) 显示当前正在进行的事件，如播放音乐、导航、下载等。

指南

  通知的开发指导分为创建NotificationSlot、发布通知和取消通知等开发场景。

1.创建NotificationSlot

1.NotificationSlot slot = new NotificationSlot("slot_001", "slot_default", NotificationSlot.LEVEL_MIN); // 创建notificationSlot对象
slot.setLevel(LEVEL_HIGH);//设置通知优先级
slot.setDescription("NotificationSlotDescription");
slot.setEnableVibration(true); // 设置振动提醒
slot.setLockscreenVisibleness(NotificationRequest.VISIBLENESS_TYPE_PUBLIC);//设置锁屏模式
slot.setEnableLight(true); // 设置开启呼吸灯提醒
slot.setLedLightColor(Color.RED.getValue());// 设置呼吸灯的提醒颜色
try {
  NotificationHelper.addNotificationSlot(slot);
} catch (RemoteException ex) {
  HiLog.warn(LABEL, "addNotificationSlot occur exception.");
}

2. 发布通知

1) 构建NotificationRequest对象

request = new NotificationRequest(notificationId);
request.setSlotId(slot.getId());

2) 调用setContent()设置通知的内容。

NotificationRequest.NotificationLongTextContent content = new NotificationRequest.NotificationLongTextContent();
content.setTitle(title)
       .setText(messageContent);
NotificationRequest.NotificationContent notificationContent = new NotificationRequest.NotificationContent(
    content);
request.setGroupValue("group information");
request.setContent(notificationContent); // 设置通知的内容
request.setTapDismissed(!tapDismissed);//设置用户点击通知后自动消失

3）调用publishNotification()发布通知。

 try {
  NotificationHelper.publishNotification(request);
  } catch (RemoteException ex) {
  HiLog.warn(LABEL, "publishNotification occur    exception.");
}

3. 取消通知

1）

调用cancelNotification()取消指定的单条通知。
try {
    NotificationHelper.cancelNotification(notificationId);
} catch (RemoteException ex) {
    HiLog.error(LABEL, "Exception occurred during cancelNotification invocation.");
}

2）

调用cancelAllNotifications()取消所有通知。
try {
    NotificationHelper.cancelAllNotifications();
} catch (RemoteException ex) {
    HiLog.error(LABEL, "Exception occurred during cancelAllNotifications invocation.");
}

4. 通过IntentAgent触发通知的跳转

//点击通知，跳转至指定的Ability 
Intent intent1 = new Intent();
// 指定要启动的Ability的BundleName和AbilityName字段
Operation operation = new Intent.OperationBuilder()
    .withDeviceId("")
    .withBundleName("com.example.myapplication")
    .withAbilityName("com.example.myapplication.SecondAbility")
    .build();
// 将Operation对象设置到Intent中
intent1.setOperation(operation);
List<Intent> intentList = new ArrayList<>();
intentList.add(intent1);
// 定义请求码
int requestCode = 200;
// 设置flags
List<IntentAgentConstant.Flags> flags = new ArrayList<>();
flags.add(IntentAgentConstant.Flags.UPDATE_PRESENT_FLAG);
// 指定启动一个有页面的Ability
IntentAgentInfo paramsInfo = new IntentAgentInfo(requestCode,
    IntentAgentConstant.OperationType.START_ABILITY, flags, intentList, null);
// 获取IntentAgent实例
IntentAgent agent = IntentAgentHelper.getIntentAgent(context, paramsInfo);
//5.设置通知的IntentAgent
request.setIntentAgent(agent);

实现效果图：

附上源码：

1. NotificationUtils

 public class NotificationUtils {

  private static final int LEVEL_HIGH = 4;
  private static NotificationRequest request;
  private static final int MY_MODULE = 0x00201;
  private static final HiLogLabel LABEL = new HiLogLabel(HiLog.LOG_APP, MY_MODULE, "MY_TAG");
  private static final boolean tapDismissed = false;

  //3.调用publishNotification()发送通知
  public static void publishNotification() {
    try {
      NotificationHelper.publishNotification(request);
    } catch (RemoteException ex) {
      HiLog.warn(LABEL, "publishNotification occur exception.");
    }
  }

  public static void initNotificationSlot(Context context, int notificationId, String title,
      String messageContent) {
    //1.创建NotificationSlot
    NotificationSlot slot = new NotificationSlot("slot_001", "slot_default", NotificationSlot.LEVEL_MIN); // 创建notificationSlot对象
    slot.setLevel(LEVEL_HIGH);//设置通知优先级
    slot.setDescription("NotificationSlotDescription");
    slot.setEnableVibration(true); // 设置振动提醒
    slot.setLockscreenVisibleness(NotificationRequest.VISIBLENESS_TYPE_PUBLIC);//设置锁屏模式
    slot.setEnableLight(true); // 设置开启呼吸灯提醒
    slot.setLedLightColor(Color.RED.getValue());// 设置呼吸灯的提醒颜色
    try {
      NotificationHelper.addNotificationSlot(slot);
    } catch (RemoteException ex) {
      HiLog.warn(LABEL, "addNotificationSlot occur exception.");
    }
    request = new NotificationRequest(notificationId);
    request.setSlotId(slot.getId());
    NotificationRequest.NotificationLongTextContent content = new NotificationRequest.NotificationLongTextContent();
    content.setTitle(title)
           .setText(messageContent);
    NotificationRequest.NotificationContent notificationContent = new NotificationRequest.NotificationContent(
        content);
    request.setGroupValue("group information");
    request.setContent(notificationContent); // 设置通知的内容
    request.setTapDismissed(!tapDismissed);//设置用户点击通知后自动消失
    //4.返回应用，首先获取IntentAgent
    Intent intent1 = new Intent();
    // 指定要启动的Ability的BundleName和AbilityName字段
    Operation operation = new Intent.OperationBuilder()
        .withDeviceId("")
        .withBundleName("com.example.myapplication")
        .withAbilityName("com.example.myapplication.SecondAbility")
        .build();
    // 将Operation对象设置到Intent中
    intent1.setOperation(operation);
    List<Intent> intentList = new ArrayList<>();
    intentList.add(intent1);
    // 定义请求码
    int requestCode = 200;
    // 设置flags
    List<IntentAgentConstant.Flags> flags = new ArrayList<>();
    flags.add(IntentAgentConstant.Flags.UPDATE_PRESENT_FLAG);
    // 指定启动一个有页面的Ability
    IntentAgentInfo paramsInfo = new IntentAgentInfo(requestCode,
        IntentAgentConstant.OperationType.START_ABILITY, flags, intentList, null);
    // 获取IntentAgent实例
    IntentAgent agent = IntentAgentHelper.getIntentAgent(context, paramsInfo);
    //5.设置通知的IntentAgent
    request.setIntentAgent(agent);
  }
}

2. MainAbilitySlice

public class MainAbilitySlice extends AbilitySlice implements ClickedListener {

  @Override
  public void onStart(Intent intent) {
    super.onStart(intent);
    super.setUIContent(ResourceTable.Layout_ability_main);
    //通知
    Text notification = (Text) findComponentById(ResourceTable.Id_text_notification);
    notification.setClickedListener(this);
    //通知标题
    String title ="测试通知";
    //通知内容文本
    String content="通知的内容已经到了！";
    NotificationUtils.initNotificationSlot(this,1,title,content);
  }

  @Override
  public void onActive() {
    super.onActive();
  }

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

  @Override
  public void onClick(Component component) {
    switch (component.getId()){
      case ResourceTable.Id_text_notification:
        NotificationUtils.publishNotification();
        break;
    }
  }
}

3. ability_main.xml

<?xml version="1.0" encoding="utf-8"?>
<DirectionalLayout
  xmlns:ohos="http://schemas.huawei.com/res/ohos"
  ohos:height="match_parent"
  ohos:orientation="vertical"
  ohos:width="match_parent">
  <Text
    ohos:id="$+id:text_notification"
    ohos:width="match_parent"
    ohos:height="match_content"
    ohos:text_size="25fp"
    ohos:top_margin="300vp"
    ohos:left_margin="15vp"
    ohos:right_margin="15vp"
    ohos:background_element="$graphic:background_text"
    ohos:text="通知"
    ohos:text_weight="1000"
    ohos:text_alignment="horizontal_center"/>
</DirectionalLayout>

4. background_text.xml

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:ohos="http://schemas.huawei.com/res/ohos"
  ohos:shape="rectangle">
  <corners
    ohos:radius="20"/>
  <solid
    ohos:color="#a5b3a9"/>
</shape>

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