Comments on: C# Design Patterns – Singleton

By: Hajimalang

Hajimalang — Sat, 14 May 2022 07:59:14 +0000

In reply to Marinko Spasojević.

Pls reply to https://code-maze.com/singleton/#comment-5399

By: Hajimalang

Hajimalang — Sat, 14 May 2022 07:57:37 +0000

In reply to Hajimalang.

Give solution to this

By: Hajimalang

Hajimalang — Sat, 02 Apr 2022 09:02:12 +0000

Hi,

It’s very helpful for me. I am a little confused. We used the singleton pattern for getting system configured data from DB. But it will be changed in the Admin configuration (may be active/inactive by admin).

eg. We have configuration ‘Turn on Send Message’.

We have to get this globally throughout application. It’s possible through singleton pattern

By: Marinko Spasojević

Marinko Spasojević — Sun, 01 Sep 2019 06:11:21 +0000

In reply to Jordi Armangué.

Thank you very much for this suggestion. I have fixed the article. I have been changing the name of the Singleton class and forgot to change the same in the Program.cs. For some reason your comment was considered as spam (I don’t know why) so I just saw it in the admin panel. Best regards,and thank you one more time.

By: Jordi Armangué

Jordi Armangué — Fri, 30 Aug 2019 12:27:21 +0000

Hi Marinko, I suggest you to update the following snippet in your article:

class Program
{
static void Main(string[] args)
{
var db = SingletonDatabase.Instance;
var db2 = SingletonDatabase.Instance;
var db3 = SingletonDatabase.Instance;
var db4 = SingletonDatabase.Instance;
}
}

in order to use the same class name than in the previous steps “SingletonDataContainer” instead of “SingletonDatabase”. It’s outdated and it has been confusing to me.

Thanks for the article!

By: Dan

Dan — Tue, 26 Feb 2019 06:14:05 +0000

The problem with Singletons is, they are so easy to use that inexperienced programmers overuse them as ‘global class’.
And as you haven’t written any line about unit testing…
Don’t use Singletons (or only carefully) when you’re willing to write UnitTests, mocking gets hard. Use dependency injection of an instance rather than getInstance.

Dan

By: Marinko

Marinko — Tue, 26 Feb 2019 02:13:27 +0000

In reply to Dan.

Hello Dan. Yes, this is a problem with this pattern, but people use it and even .NET Core provides you with a possibility to register service as a singleton through the AddSingleton method (but as you said, then it could be used width Dependency Injection). Anyhow, I agree with you that it should be used with caution. Thank you for your comment, it is going to be helpful for our readers for sure.