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QuestionHelp with Windows Form and IF statement Pin
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QuestionStore one value from rows of data in a table Pin
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QuestionCan we overload an abstract method of an abstract class? Pin
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QuestionAn abstract singleton factory Pin
Marco Bertschi24-Jun-15 1:48
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Marco Bertschi24-Jun-15 2:48
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AnswerRe: An abstract singleton factory Pin
Richard Deeming24-Jun-15 4:29
mveRichard Deeming24-Jun-15 4:29 
Marco Bertschi wrote:
What I want to have is a single instance of each and every class deriving from Factory.

The code you've posted won't do that.

Firstly, if you pass anything other than typeof(Factory) to your GetInstance method, you'll get an InvalidOperationException - typeof(DerivedFactory) != typeof(Factory).

Secondly, if you pass typeof(Factory) to your GetInstance method, you'll get a MissingMethodException - you can't create an instance of an abstract class.

Thirdly, even if you fix the previous errors, you would only ever be able to have a single instance of one derived class in a single AppDomain. The static field is specific to the Factory class; you don't get a different copy for each derived class.



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AnswerRe: An abstract singleton factory Pin
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QuestionExtension Methods in .NET 2 Pin
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