通知未显示在屏幕上且不存在错误

Question

请帮帮我！！！
我正在为明天的学校执行一个项目，我找不到解决这个问题的方法，因为 logcat 没有给出错误。

我正在创建一个可以创建提醒的应用程序。提醒已创建并保存在数据库中，但通知不会显示在屏幕上。下面是我们创建的 ReminderAlarmService Class 的代码，用于设置提醒和通知，通知部分在最后。

我想知道为什么没有显示通知，即使我检查了数据库并且提醒存储在那里。

以下代码对应我创建通知的地方：

package com.example.projetolinguagensprogramacao1.Lembretes;

import android.app.IntentService;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.net.Uri;
import android.provider.Settings;

import androidx.annotation.Nullable;
import androidx.core.app.NotificationCompat;
import androidx.core.app.NotificationManagerCompat;
import androidx.core.app.TaskStackBuilder;

import com.example.projetolinguagensprogramacao1.R;

public class ReminderAlarmService extends IntentService {

    private static final String TAG = ReminderAlarmService.class.getSimpleName();

    private static final int NOTIFICATION_ID = 42;
    //This is a deep link intent, and needs the task stack
    public static PendingIntent getReminderPendingIntent(Context context, Uri uri) {
        Intent action = new Intent(context, ReminderAlarmService.class);
        action.setData(uri);
        return PendingIntent.getService(context, 0, action, PendingIntent.FLAG_UPDATE_CURRENT);
    }

    public ReminderAlarmService() {
        super(TAG);
    }

    @Override
    protected void onHandleIntent(@Nullable Intent intent) {
        NotificationManager manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
        Uri uri = intent.getData();

        //Display a notification to view the task details
        Intent action = new Intent(this, AddReminderActivity.class);
        action.setData(uri);
        PendingIntent operation = TaskStackBuilder.create(this)
                .addNextIntentWithParentStack(action)
                .getPendingIntent(0, PendingIntent.FLAG_UPDATE_CURRENT);

        //Grab the task description
        Cursor cursor = getContentResolver().query(uri, null, null, null, null);

        String description = "";
        try {
            if (cursor != null && cursor.moveToFirst()) {
                description = AlarmReminderContract.getColumnString(cursor, AlarmReminderContract.AlarmReminderEntry.KEY_TITLE);
            }
        } finally {
            if (cursor != null) {
                cursor.close();
            }
        }

        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this)
                .setContentTitle(getString(R.string.reminder_title))
                .setContentText(description)
                .setSmallIcon(R.drawable.ic_add_alert_black_24dp)
                .setContentIntent(operation)
                .setVibrate(new long[] { 1000, 1000, 1000, 1000, 1000 })
                .setSound(Settings.System.DEFAULT_NOTIFICATION_URI)
                .setAutoCancel(true)
                .setContentIntent(operation);

        manager.notify(1, notificationBuilder.build());
    }
}

Answer 1

从 Android 8.0（API 级别 26）开始，通知将不会显示，除非您提供 NotificationChannel 作为 NotificationCompat.Builder 构造函数的第二个参数。

所以，要解决这个问题，请创建一个 NotificationChannel；我将ID设置为"PRIMARY_CHANNEL_ID"如下

// Notification channels are only available in OREO and higher.
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.O) {

    NotificationChannel notificationChannel = new NotificationChannel
            ("PRIMARY_CHANNEL_ID",
                    "Service",
                    NotificationManager.IMPORTANCE_HIGH);

    notificationChannel.enableLights(true);
    notificationChannel.setLightColor(Color.RED);
    notificationChannel.enableVibration(true);
    notificationChannel.setDescription("Description");

    manager.createNotificationChannel(notificationChannel);

}

使用频道 ID "PRIMARY_CHANNEL_ID" 作为 NotificationCompat.Builder 构造函数的第二个参数。

    NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this, "PRIMARY_CHANNEL_ID")
            .setContentTitle(getString(R.string.reminder_title))
            .setContentText(description)
            .setSmallIcon(R.drawable.ic_add_alert_black_24dp)
            .setContentIntent(operation)
            .setVibrate(new long[] { 1000, 1000, 1000, 1000, 1000 })
            .setSound(Settings.System.DEFAULT_NOTIFICATION_URI)
            .setAutoCancel(true)
            .setContentIntent(operation);

通知未显示在屏幕上且不存在错误

The notification is not displayed on the screen and not exist errors

java

sqlite

notifications

android