CODEWITHSUNDEEP
c#.netsingletonvsto
user1307904
user1307904

Reputation:

Singleton implementation for VSTO/COM

Basically, what I am trying to do is to create a Singleton instance of Word so my other classes cannot create a duplicate process. 

public sealed class WordSingleton
{
    private static Word.Application _App = null;

    WordSingleton() { }

    public static Word.Application App
    {
        get
        {
            if (_App == null)
                _App = new Word.Application();                 

            return _App;
        }
    }

    // dispose the singleton from a single place
    public static void Dispose()
    {
        if (_App != null)
            _App.Quit();

        Marshal.ReleaseComObject(_App);
    }
}

I have been struggling with this and finally came up with this. I was wondering if the experts can advise me on my usage - if its correct, incorrect, requires improvement? I am coming from a different technology so this is quite new to me.

Upvotes: 2

Views: 442

Answers (2)

Chris Gessler
Chris Gessler

Reputation: 23123

Here's how I would do this. Use the readonly keyword so that it can't be replaced. This is also threadsafe.

public sealed class WordSingleton 
{     

  public static readonly Word.Application Instance = new Word.Application();      

  private WordSingleton() { } 

}

Upvotes: 3

abatishchev
abatishchev

Reputation: 100328

Why don't initialize in class scope?

private static Word.Application _App = new Word.Application();

Such a singleton will be controlled by CLR. Dispose it as usually.

Upvotes: 1

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