How to consume Singleton class

Question

1.00/5 (1 vote)

See more:

Hi All,
I am new to singleton class how to call the display method can u guide or send snippets

C#

public sealed class Singleton
{
    private static readonly Lazy<Singleton> lazy =
        new Lazy<Singleton>(() => new Singleton());

    public static Singleton Instance { get { return lazy.Value; } }

    private Singleton()
    {
    }
  public string display(string msg)
  {
     return "you have entered " + msg;
   }
}

Posted 20-Nov-13 19:07pm

kingsa

Updated 20-Nov-13 21:51pm

VICK

v2

Add a Solution

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Sergey Alexandrovich Kryukov · Answer 1 · 2013-11-20T19:44:00

Solution 2

This singleton definition makes no sense. In particular, display makes no sense, incorrect (would work, but it needs to be static, because "this" is not used) and unrelated to singleton functionality. Exposing Instance would work but means bad style.

First, read this: http://en.wikipedia.org/wiki/Singleton_pattern[^].

And here is a good singleton sample: http://csharpindepth.com/Articles/General/Singleton.aspx[^].

—SA

Posted 20-Nov-13 19:44pm

Sergey Alexandrovich Kryukov

Comments

lukeer 21-Nov-13 2:04am

Despite your harsh comment on the op's code, it's exactly resembling the last example from your second link.

Since I have no experience with the Lazy<> type, is that example really that bad?

Sergey Alexandrovich Kryukov 21-Nov-13 14:19pm

No, using Lazy is not a bad idea at all. The OP's sample does resemble right thing, but only resembles. I pointed out concrete problems. The sample lacks encapsulation, which practically makes it pointless. There is no a single step from using no Singleton pattern. Do you understand that the same behavior can be achieved without singleton, just by using one static object. And making a wrapping class around it only pays off when you add some useful encapsulation. And the problem with display is just a separate design bug. For example, FxCop rightfully detect non-static method not actually using "this" as a performance bug item.
—SA

Jobless Creature · Answer 2 · 2013-11-20T19:25:00

Solution 1

Just try Singleton.display("input string")..

For singleton, you can consume as classname.methodname()..

does this help?

Posted 20-Nov-13 19:25pm

Jobless Creature

Comments

Sergey Alexandrovich Kryukov 21-Nov-13 1:40am

No, it won't even compile, with OP's Singleton definition. Should I even explain why?
Please, never give answers you did not even try to compile. Not answering is much better than confusing people with wrong answers.
—SA