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Android notification application

Posted on Aug. 8, 2022, 8:02 p.m. by Nigel Booth
Category: android Tag: android

1. Create basic notifications

Notifications in their most basic, condensed form (also known as folded form) display an icon, a title, and a small amount of content text. In this section, you'll learn how to create notifications that the user can click to start an Activity in the application.

Set up notifications content First, you need to use NotificationCompat. Builder object set up notifications content and channels. The following example shows how to create a notification that contains: small ICONS, set with setSmallIcon(). This is the only user-visible content required. Title, set with setContentTitle(). Body text, set with setContentText(). Notification priority, set by setPriority(). How intrusive priority determination notifications are on Android 7.1 and lower versions. (For Android 8.0 and later, channel importance must be set)

NotificationCompat.Builder builder = new NotificationCompat.Builder(this, CHANNEL_ID)
            .setSmallIcon(R.drawable.notification_icon)
            .setContentTitle(textTitle)
            .setContentText(textContent)
            .setPriority(NotificationCompat.PRIORITY_DEFAULT);
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Please note that NotificationCompat. Builder constructor ID ask you to provide channels. This is required for compatibility with Android 8.0 (API level 26) and later, but will be ignored by older versions. By default, the text content of the notification is truncated to fit on one line. If you want longer notifications, you can use setStyle() to add style templates to enable expandable notifications. For example, the following code creates a larger text area:

NotificationCompat.Builder builder = new NotificationCompat.Builder(this, CHANNEL_ID) .setSmallIcon(R.drawable.notification_icon) .setContentTitle("My notification") .setContentText("Much longer  text that cannot fit one line..." ) .setStyle(new NotificationCompat.BigTextStyle() .bigText("Much longer text that cannot fit one line..." )) .setPriority(NotificationCompat.PRIORITY_DEFAULT);Copy the code

To create a channel and set up the importance Must first to createNotificationChannel () NotificationChannel instance of registered in the system application notification channel, and then to provide notification on Android 8.0 and higher versions. So the following code is blocked by a condition on the SDK_INT version:

private void createNotificationChannel() { // 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) { CharSequence name = getString(R.string.channel_name); String description = getString(R.string.channel_description); int importance = NotificationManager.IMPORTANCE_DEFAULT; NotificationChannel channel = new NotificationChannel(CHANNEL_ID, name, importance); channel.setDescription(description); // Register the channel with the system; you can't change the importance // or other notification behaviors after this NotificationManager notificationManager = getSystemService(NotificationManager.class); notificationManager.createNotificationChannel(channel); }}Copy the code

2. Create expanded notifications

A basic notification typically consists of a header, a line of text, and one or more response actions that the user can perform. For more information, you can also apply one of the multiple notification templates described on this page to create large expanded notifications.

First, create a notification using all the basics described in Creating a Notification. SetStyle () is then called with a style object, providing information corresponding to each template (as shown below).

Add big picture

If you want to add images in the notice, please send NotificationCompat. An instance of BigPictureStyle passed to setStyle ().

Notification notification = new NotificationCompat.Builder(context, CHANNEL_ID)
            .setSmallIcon(R.drawable.new_post)
            .setContentTitle(imageTitle)
            .setContentText(imageDescription)
            .setStyle(new NotificationCompat.BigPictureStyle()
                   .bigPicture(myBitmap))
            .build();
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If you want to make the image displayed as thumbnails only pack up the notice (as shown in figure 1), please call setLargeIcon () and pass to its image, at the same time call BigPictureStyle. BigLargeIcon () and pass null to its, so large ICONS will disappear when in notice:

Notification notification = new NotificationCompat.Builder(context, CHANNEL_ID)
            .setSmallIcon(R.drawable.new_post)
            .setContentTitle(imageTitle)
            .setContentText(imageDescription)
            .setLargeIcon(myBitmap)
            .setStyle(new NotificationCompat.BigPictureStyle()
                    .bigPicture(myBitmap)
                    .bigLargeIcon(null))
            .build();
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Utility class

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.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Build;
import android.support.v4.app.NotificationCompat;
import android.support.v4.app.NotificationManagerCompat;
import android.widget.RemoteViews;

/**
 * @author 阿童木
 * @date 2020/8/28 9:57
 * @功能: 自定义通知
 */

public class NotificationManager {
    private static PushNotionManager instance;
    private String CHANNEL_ID = "custom_notification";
    Context context;

    public static PushNotionManager getInstance() {
        if (instance == null) {
            instance = new PushNotionManager();
        }
        return instance;
    }

    /**
     * @author 阿童木
     * @create 2020/8/28 14:10
     * @Describe 显示通知
     * 显示通知,请调用 NotificationManagerCompat.notify(),并将通知的唯一 ID 和 NotificationCompat.Builder.build() 的结果传递给它
     */
    int notificationId=1;
    public void showNotification(Context context) {
        NotificationManager notificationManager = null;
        if (android.os.Build.VERSION.SDK_INT = android.os.Build.VERSION_CODES.M) {
            notificationManager = context.getSystemService(NotificationManager.class);
        }
        if (Build.VERSION.SDK_INT = Build.VERSION_CODES.O) {
            //创建渠道并设置重要性
            //必须先通过向 createNotificationChannel() 传递 NotificationChannel 的实例在系统中注册应用的通知渠道,
            //然后才能在 Android 8.0 及更高版本上提供通知。
            //因此以下代码会被 SDK_INT 版本上的条件阻止:
            CharSequence name = "channel_name";
            String description = "channel_name_cch";
            int importance = NotificationManager.IMPORTANCE_DEFAULT;
            NotificationChannel channel = new NotificationChannel(CHANNEL_ID, 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);
        }
        // notificationId is a unique int for each notification that you must define(notificationId是您必须定义的每个通知的唯一int)
        //请记得保存您传递到 NotificationManagerCompat.notify() 的通知 ID,因为如果之后您想要更新或移除通知,将需要使用这个 ID。
        notificationManager.notify(notificationId, getBigNotification(context));
    }

    /**
     * @author 阿童木
     * @create 2020/8/28 11:57
     * @Describe Create a custom notification layout(创建自定义通知布局)
     * 根据手机系统不同,有的可以直接展开大图模式,有的需要下拉才能展开。
     */
    private Notification getCustomNotification(Context context) {
        this.context = context;
        // 获取要在自定义通知中使用的布局(默认)
        RemoteViews notificationLayout = new RemoteViews(context.getPackageName(), R.layout.notification_small);
        //获取要在自定义通知中使用的布局(展开时的)
        RemoteViews notificationLayoutExpanded = new RemoteViews(context.getPackageName(), R.layout.notification_large);

        // Apply the layouts to the notification
        //使用 NotificationCompat.Builder 构建基本通知。
        return new NotificationCompat.Builder(context, CHANNEL_ID)
                .setSmallIcon(R.mipmap.notifation_small_icon)
                //调用 setStyle(),向其传递一个 NotificationCompat.DecoratedCustomViewStyle 实例。
                .setStyle(new NotificationCompat.DecoratedCustomViewStyle())
                //调用 setCustomContentView() 以设置收起后通知的布局。
                .setCustomContentView(notificationLayout)
                //自定义布局扩充为 RemoteViews
                .setCustomBigContentView(notificationLayoutExpanded)
                .build();
    }

    /**
     * @author 阿童木
     * @create 2020/8/28 13:59
     * @Describe 创建展开式通知
     */
    public Notification getBigNotification(Context context) {
        this.context = context;
        Notification notification = new NotificationCompat.Builder(context, CHANNEL_ID)
                .setSmallIcon(R.mipmap.notifation_small_icon)
                .setContentTitle("imageTitle")
                .setContentText("创建展开式通知基本通知通常包括标题、一行文本,以及用户可以执行的一项或多项响应操作。如需提供更多信息,您还可以应用本页介绍的多个通知模板之一来创建大型展开式通知。首先,使用创建通知中介绍的所有基本内容创建通知。然后,使用一个样式对象调用 setStyle(),并提供与每个模板相对应的信息(如下所示)。")
                //添加大图片\添加一大段文本
                .setStyle(getBigContentStyle(1))
                //通知优先级,通过 setPriority()
                .setPriority(NotificationCompat.PRIORITY_DEFAULT )
                // Set the intent that will fire when the user taps the notification  设置通知的点按操作 创建基本 Intent,以在用户点按通知时打开 Activity
                .setContentIntent(getPendingIntent())
                //此代码会调用 setAutoCancel(),它会在用户点按通知后自动移除通知。
                .setAutoCancel(true)
                .build();
        return notification;
    }

    /**
     * @author 阿童木
     * @create 2020/8/28 13:59
     * @Describe 添加大图片\添加一大段文本
     */
    private NotificationCompat.Style getBigContentStyle(int i) {
        if (i == 1) {
            Bitmap bitmap = BitmapFactory.decodeResource(context.getResources(), R.drawable.big_picture);
            //添加大图片 如需在通知中添加图片,请将 NotificationCompat.BigPictureStyle 的一个实例传递给 setStyle()。
            return new NotificationCompat.BigPictureStyle().bigPicture(bitmap);
        } else {
            //添加一大段文本 应用 NotificationCompat.BigTextStyle,以在通知的展开内容区域显示文本
            return new NotificationCompat.BigTextStyle().bigText("添加一大段文本\n" +
                    "应用 NotificationCompat.BigTextStyle,以在通知的展开内容区域显示文本:" + "Notification notification = new NotificationCompat.Builder(context, CHANNEL_ID)\n" +
                    "            .setSmallIcon(R.drawable.new_mail)\n" +
                    "            .setContentTitle(emailObject.getSenderName())\n" +
                    "            .setContentText(emailObject.getSubject())\n" +
                    "            .setLargeIcon(emailObject.getSenderAvatar())\n" +
                    "            .setStyle(new NotificationCompat.BigTextStyle()\n" +
                    "                    .bigText(emailObject.getSubjectAndSnippet()))\n" +
                    "            .build();");
        }
    }

    /**
     * @author 阿童木
     * @create 2020/8/28 14:03
     * @Describe 设置通知的点按操作
     */
    public PendingIntent getPendingIntent() {
        // Create an explicit intent for an Activity in your app
        Intent intent = new Intent(context, MainActivity.class);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
        PendingIntent pendingIntent = PendingIntent.getActivity(context, 0, intent, 0);
        return pendingIntent;
    }


}

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