android - 如何在不在线的情况下发送通知?
问题描述
我正在构建一个应用程序,用户将在其中放置他们的测试和作业等等。我想知道我的应用程序是否有可能在测试前一周和一天发出通知?
我到处看它只是关于firebase通知和推送通知。
我不想要这些在线通知,我需要应用程序自己离线发送它们。这可能吗?
解决方案
让我添加一些解决方法,您可以在外面找到更多教程..
首先创建接收器类扩展BroadcastReceiver
。
public class ReminderReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
int Request_Code = intent.getExtras().getInt("TIME",0);
showNotification(context, MainActivity.class,
"New Notification Alert..!", "scheduled for " + Request_Code + " seconds",Request_Code);
}
public void showNotification(Context context, Class<?> cls, String title, String content,int RequestCode)
{
Uri alarmSound = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION);
Intent notificationIntent = new Intent(context, cls);
notificationIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
TaskStackBuilder stackBuilder = TaskStackBuilder.create(context);
stackBuilder.addParentStack(cls);
stackBuilder.addNextIntent(notificationIntent);
PendingIntent pendingIntent = stackBuilder.getPendingIntent(
RequestCode,PendingIntent.FLAG_ONE_SHOT);
NotificationManager notificationManager = (NotificationManager)
context.getSystemService(Context.NOTIFICATION_SERVICE);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
CharSequence name = context.getString(R.string.channel_name);
String description = context.getString(R.string.channel_description);
int importance = NotificationManager.IMPORTANCE_DEFAULT;
NotificationChannel channel = new NotificationChannel("my_channel_01", name, importance);
channel.setDescription(description);
// Register the channel with the system; you can't change the importance
// or other notification behaviors after this
notificationManager.createNotificationChannel(channel);
}
NotificationCompat.Builder builder = new NotificationCompat.Builder(context,"my_channel_01");
Notification notification = builder.setContentTitle(title)
.setContentText(content).setAutoCancel(true)
.setSound(alarmSound).setSmallIcon(R.drawable.ic_launcher_background)
.setContentIntent(pendingIntent).build();
notificationManager.notify(RequestCode,notification);
}
}
在活动标签下方的清单类中声明接收者..
<receiver android:enabled="true" android:name=".ReminderReceiver"/>
然后将提醒设置为警报管理器。
public void setReminder(Context context,Class<?> cls,int sec)
{
Intent intent = new Intent(context, cls);
intent.putExtra("TIME",sec);
PendingIntent pendingIntent = PendingIntent.getBroadcast(context, sec, intent,
PendingIntent.FLAG_ONE_SHOT);/* Find more about flags: https://developer.android.com/reference/android/app/PendingIntent */
AlarmManager am = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
am.set( AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + (sec * 1000), pendingIntent );//Add time in milliseconds. if you want to minute or hour mutiply by 60.. For ex: You want to trigger 5 Min then here you need to change 5 * 60 * 1000
}
最后设置你的提醒
setReminder(_Context,ReminderReceiver.class,time);
更新
要支持 android 版本 8.0 及更高版本,您必须创建通知通道。在此处查找更多 信息
在上面的代码中添加:
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
CharSequence name = context.getString(R.string.channel_name);
String description = context.getString(R.string.channel_description);
int importance = NotificationManager.IMPORTANCE_DEFAULT;
NotificationChannel channel = new NotificationChannel("my_channel_01", name, importance);
channel.setDescription(description);
// Register the channel with the system; you can't change the importance
// or other notification behaviors after this
notificationManager.createNotificationChannel(channel);
}
注意对小图标使用 drawable,而不是使用 mipmap 或自适应图标。Android Oreo 通知崩溃系统 UI
取消预定通知
public void cancelReminder(Context context,Class<?> cls)
{
Intent intent1 = new Intent(context, cls);
intent1.putExtra("TIME",time);
PendingIntent pendingIntent = PendingIntent.getBroadcast(context,
time, intent1, PendingIntent.FLAG_ONE_SHOT);
AlarmManager am = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
if(pendingIntent != null) {
am.cancel(pendingIntent);
}
}
并使用上述方法删除
cancelReminder(_Context,ReminderReceiver.class);
注意:_Context 应与
setreminder()
方法中使用的相同
推荐阅读
- angular - Angular中的参数周围的花括号
- html - 缩小屏幕尺寸时内容旁边的空白
- swift - 泛型类型“结果”专门具有太多类型参数(得到 2,但预期为 1)
- android - 从第一个请求中获取对象后发出请求
- javascript - 如何存储重量值并转换为标准/公制重量?
- python - 有没有可能对此进行矢量化?
- reactjs - 目标点击时从父级到子级的事件冒泡
- javascript - 链接按钮 Onclick 与选择菜单 Onchange
- flask - 使用 Auth0 授权用户访问某些页面的正确方法
- javascript - Passport Google 策略 - passport.use 回调何时运行?回调URL?