Question

我对Android中的本地通知有疑问。我正在开发一个应用程序，其中第一部分必须接收我自己的服务器公司的所有会议（我已经实现），第二部分我必须在每次会议前一天通知，但有本地通知。

如何在指定日期安排本地通知？

Answer 1

要安排本地通知，您需要了解用于安排通知的一些内容，例如

BroadcastReceivers IntentFilters AlarmManager NotificationService 的PendingIntent

在MainActivity中执行以下操作

import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D
import numpy as np
import itertools

#read in data from csv organised in columns labelled 'lat','lon','elevation'
data = np.recfromcsv('elevation-sample.csv', delimiter=',')

# create a 3d axis on a figure
fig = plt.figure()
ax = fig.add_subplot(111, projection='3d')

# Find unique (i.e. constant) latitude points
id_list = np.unique(data['lat'])

# stride is how many lines to miss.  set to 1 to get every line
# higher to miss more
stride = 5

# Extract each line from the dataset and plot it on the axes
for id in id_list[::stride]:
    this_line_data = data[np.where(data['lat'] == id)]
    lat,lon,ele = zip(*this_line_data)
    ax.plot(lon,lat,ele, color='black')

# set the viewpoint so we're looking straight at the longitude (x) axis
ax.view_init(elev=45., azim=90)

ax.set_xlabel('Longitude')
ax.set_ylabel('Latitude')
ax.set_zlabel('Elevation')
ax.set_zlim([0,1500])

plt.show()

上述代码将在15秒后安排警报。 15秒后，它将广播notificationIntent。

Intent构造函数中指定的操作在AndroidManifest.xml中定义

要了解本地通知的完整工作情况并查看示例通知代码，请查看此文章 - http://www.singhajit.com/schedule-local-notification-in-android/

Answer 2

编辑：我现在已经尝试了 WorkManager，但它在时间上似乎也非常不可靠。很抱歉。

如果您想安排不需要非常精确的时间的本地通知，最好不要使用 AlarmManager，因为 many Android phones 会运行得太晚，或者绝不。而是使用 androidx 中的 WorkManager。

Josip Žitković 在 this blog 中出色地解释了所有这些。

首先，随时随地安排通知：

WorkRequest work = new PeriodicWorkRequest.Builder(MyWorker.class, 1, TimeUnit.DAYS)
    .setInitialDelay(delay, TimeUnit.MINUTES)
    .build()
;
WorkManager.getInstance(context).enqueue(work);

现在创建 MyWorker，它将被调用以显示实际通知：

import android.app.Notification;
import android.app.NotificationChannel;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.os.Build;
import android.util.Log;
import androidx.annotation.NonNull;
import androidx.core.app.NotificationCompat;
import androidx.core.app.NotificationManagerCompat;
import androidx.core.app.TaskStackBuilder;
import androidx.work.Worker;
import androidx.work.WorkerParameters;

public class MyWorker extends Worker {
    public MyWorker(
        @NonNull Context context,
        @NonNull WorkerParameters params) {
        super(context, params);
    }

    @Override
    public Result doWork() {
        Context context = this.getApplicationContext();

        // Intent to start when notification is tapped
        Intent notificationIntent = new Intent(context, MainActivity.class);
        TaskStackBuilder stackBuilder = TaskStackBuilder.create(context);
        stackBuilder.addParentStack(MainActivity.class);
        stackBuilder.addNextIntent(notificationIntent);
        PendingIntent pendingIntent = stackBuilder.getPendingIntent(0, PendingIntent.FLAG_UPDATE_CURRENT);

        createNotificationChannel(context);

        NotificationCompat.Builder builder = new NotificationCompat.Builder(context, "my_channel")
            .setContentTitle("hello, world")
            // Only on api < 26, see createNotificationChannel otherwise
            .setPriority(NotificationCompat.PRIORITY_DEFAULT)
            // Default sound, vibration etc
            // Only on api < 26, see createNotificationChannel otherwise
            .setDefaults(Notification.DEFAULT_ALL)
            .setContentIntent(pendingIntent);

        NotificationManagerCompat notificationManager = NotificationManagerCompat.from(context);
        notificationManager.notify(0, builder.build());

        return Result.success();
    }

    /**
     * This needs to be called at least once on android API >= 26 before creating a notification.
     */
    public static void createNotificationChannel(Context context) {
        // Create the NotificationChannel, but only on API 26+ because
        // the NotificationChannel class is new and not in the support library
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationChannel channel = new NotificationChannel("my_channel", "MyApp notifications", NotificationManager.IMPORTANCE_DEFAULT);
            channel.setDescription("They will wake you up in the night");
            channel.enableVibration(true);

            // Register the channel with the system; you can't change the importance
            // or other notification behaviors after this
            NotificationManager notificationManager = context.getSystemService(NotificationManager.class);
            notificationManager.createNotificationChannel(channel);
        }
    }
}

如何安排Android本地通知？

2 个答案: