Android 10 通知-源码解析

创建通知

下面代码来自https://developer.android.google.cn/training/notify-user/channels

//默认情况下，通知的文本内容会被截断以放在一行。如果您想要更长的通知，可以使用 setStyle() 添加样式模板来启用可展开的通知。

    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);

 //Android 8.0 及更高版本上提供通知,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

    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);
        }
    }

//以下代码段展示了如何创建基本 Intent，以在用户点按通知时打开 Activity：

    // Create an explicit intent for an Activity in your app
    Intent intent = new Intent(this, AlertDetails.class);
    intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
    PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent, 0);

    NotificationCompat.Builder builder = new NotificationCompat.Builder(this, CHANNEL_ID)
            .setSmallIcon(R.drawable.notification_icon)
            .setContentTitle("My notification")
            .setContentText("Hello World!")
            .setPriority(NotificationCompat.PRIORITY_DEFAULT)
            // Set the intent that will fire when the user taps the notification
            .setContentIntent(pendingIntent)
            .setAutoCancel(true);
//如需显示通知，请调用 NotificationManagerCompat.notify()，并将通知的唯一 ID 和 NotificationCompat.Builder.build() 的结果传递给它。

    NotificationManagerCompat notificationManager = NotificationManagerCompat.from(this);

    // notificationId is a unique int for each notification that you must define
    notificationManager.notify(notificationId, builder.build());

//如需添加操作按钮，请将 addAction() 传递给 PendingIntent 方法。

    Intent snoozeIntent = new Intent(this, MyBroadcastReceiver.class);
    snoozeIntent.setAction(ACTION_SNOOZE);
    snoozeIntent.putExtra(EXTRA_NOTIFICATION_ID, 0);
    PendingIntent snoozePendingIntent =
            PendingIntent.getBroadcast(this, 0, snoozeIntent, 0);

    NotificationCompat.Builder builder = new NotificationCompat.Builder(this, CHANNEL_ID)
            .setSmallIcon(R.drawable.notification_icon)
            .setContentTitle("My notification")
            .setContentText("Hello World!")
            .setPriority(NotificationCompat.PRIORITY_DEFAULT)
            .setContentIntent(pendingIntent)
            .addAction(R.drawable.ic_snooze, getString(R.string.snooze),
                    snoozePendingIntent);
// 显示紧急消息
您的应用可能需要显示紧急的时效性消息，例如来电或响铃警报。在这些情况下，您可以将全屏 Intent 与通知关联。调用通知时，根据设备的锁定状态，用户会看到以下情况之一：

如果用户设备被锁定，会显示全屏 Activity，覆盖锁屏。
如果用户设备处于解锁状态，通知以展开形式显示，其中包含用于处理或关闭通知的选项。
紧急消息弹出屏幕，时效时间30s。

    Intent fullScreenIntent = new Intent(this, CallActivity.class);
    PendingIntent fullScreenPendingIntent = PendingIntent.getActivity(this, 0,
            fullScreenIntent, PendingIntent.FLAG_UPDATE_CURRENT);

    NotificationCompat.Builder notificationBuilder =
            new NotificationCompat.Builder(this, CHANNEL_ID)
        .setSmallIcon(R.drawable.notification_icon)
        .setContentTitle("Incoming call")
        .setContentText("(919) 555-1234")
        .setPriority(NotificationCompat.PRIORITY_HIGH)
        .setCategory(NotificationCompat.CATEGORY_CALL)

        // Use a full-screen intent only for the highest-priority alerts where you
        // have an associated activity that you would like to launch after the user
        // interacts with the notification. Also, if your app targets Androi