Android8.0自定义通知栏如何实现，给出代码示范

以下是一个简单的 Android 8.0 自定义通知栏的示例代码：

// 创建通知渠道
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
    NotificationChannel channel = new NotificationChannel("channel_id", "channel_name", NotificationManager.IMPORTANCE_DEFAULT);
    channel.setDescription("channel_description");
    NotificationManager notificationManager = getSystemService(NotificationManager.class);
    notificationManager.createNotificationChannel(channel);
}

// 创建通知
NotificationCompat.Builder builder = new NotificationCompat.Builder(this, "channel_id")
        .setSmallIcon(R.drawable.notification_icon)
        .setContentTitle("Notification Title")
        .setContentText("Notification Text")
        .setPriority(NotificationCompat.PRIORITY_DEFAULT);

// 显示通知
NotificationManagerCompat notificationManager = NotificationManagerCompat.from(this);
notificationManager.notify(notificationId, builder.build());

请注意，这只是一个简单的示例代码，您需要根据您的需求进行修改和扩展。