android studio通知不起作用

Question

im new to android and i want the user to get a notification when he reached the maximum value. this is how i wrote the code

countUp.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if(highestText == 0 && minimumText == 0){
                Toast.makeText(getApplicationContext(),"Please enter the target numbers!",Toast.LENGTH_SHORT).show();
            }else {

                if (highestText == minimumText) {
                    NotificationCompat.Builder builder = new NotificationCompat.Builder(MainActivity.this, "number");
                    builder.setContentTitle("Maximum number ");
                    builder.setContentText("please be aware that you reached the maximum number");
                    builder.setSmallIcon(R.drawable.ic_launcher_background);
                    builder.setAutoCancel(true);
                    NotificationManagerCompat managerCompat = NotificationManagerCompat.from(MainActivity.this);
                    managerCompat.notify(1, builder.build());
                }

            }
            if(!(highestText == 0 && minimumText == 0)){
                count++;
                counter.setText("" + count);
            }
        }
    });

Answer 1

You are not using the notification channel id I'm not sure but it could be the cause of the problem. I am pasting the snippet of working code from my project, it should work properly but let me know if it will not work

public void showNotification(String Title, String Body){

    //  PendingIntent pi = PendingIntent.getActivity(this, 0, new Intent(this, splash_screen.class), 0);

    NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
    String NOTIFICATION_CHANNEL_ID = "channel_id_01";

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
        NotificationChannel notificationChannel = new NotificationChannel(NOTIFICATION_CHANNEL_ID, "My Notifications", NotificationManager.IMPORTANCE_HIGH);

        // Configure the notification channel.
        notificationChannel.setDescription("Channel description");
        notificationChannel.enableLights(true);
        notificationChannel.setLightColor(Color.RED);
        notificationChannel.setVibrationPattern(new long[]{0, 1000, 500, 1000});
        notificationChannel.enableVibration(true);
        notificationManager.createNotificationChannel(notificationChannel);
    }
    NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this, NOTIFICATION_CHANNEL_ID);

    notificationBuilder.setAutoCancel(true)
            .setDefaults(Notification.DEFAULT_ALL)
            .setWhen(System.currentTimeMillis())
            .setSmallIcon(R.drawable.notification_icon)
            //setticker is a text which is pronounce by accessibility service for differently abled people
            .setTicker("NEW NOTIFICATION")
           // .setAutoCancel(false)
            //        .setContentIntent(pi)
            .setPriority(Notification.PRIORITY_MAX)
            .setContentTitle(Title)
            .setContentText(Body)
            .setContentInfo("Info");

    notificationManager.notify(/*notification id*/1, notificationBuilder.build());
}