先上效果图

参考这篇文章解决

	/**
     * 发送通知
     * @param content
     */
    @SuppressLint("WrongConstant")
    private void sendNotification(String content) {
        try {
            String[] contents = content.split(",");
            Intent intent = new Intent();
            intent.setClass(this, TabHostActivity.class);
            intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED | Intent.FLAG_ACTIVITY_CLEAR_TOP);
            PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT);
            final NotificationManager notifiManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
            String id = getPackageName();
            String name = "call_msg";
            //Android 8.0 的要手动设置NotificationChannel
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                //NotificationManager.IMPORTANCE_MAX 最高支持 声音和悬浮
                NotificationChannel channel = new NotificationChannel(id, name, NotificationManager.IMPORTANCE_MAX);
				notifiManager.createNotificationChannel(channel);
            }
            Notification notification = new NotificationCompat.Builder(this)
                    .setAutoCancel(true)
                    .setPriority(Notification.PRIORITY_MAX)
                    .setSmallIcon(R.drawable.pre_icon)
                    .setContentTitle(contents[0])
                    .setContentText(contents[1])
                    .setVisibility(VISIBILITY_PUBLIC)
                    .setWhen(System.currentTimeMillis())
                    //向通知添加声音、闪灯和振动效果
                    .setDefaults(Notification.DEFAULT_VIBRATE | Notification.DEFAULT_ALL | Notification.DEFAULT_SOUND)
                    .setContentIntent(pendingIntent)
                    .setChannelId(id)
                    .build();
            notifiManager.notify(1, notification);

        } catch (Exception e) {
            e.printStackTrace();
        }
    }

主要适配sdk26（Android 8.0）之后的
然后使用.setChannelId(id)方法

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                //NotificationManager.IMPORTANCE_MAX 最高支持 声音和悬浮
                NotificationChannel channel = new NotificationChannel(id, name, NotificationManager.IMPORTANCE_MAX);
                notifiManager.createNotificationChannel(channel);
            }