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Is having Message Box in business class wrong?

Is having reference to System.Windows.Forms in a business class and using MessageBox.Show wrong?

Currently have a event processing decorator class decorating a service class. When certain events fired decorator would like to ask user if they want to proceed processing certain functionality.

Is it ok for this decorator class have these message boxes?

Solution

  • You should never have a UI in a business class.

    The reason for this is you never know how your business class might be used down the road. Perhaps it will be used in a new website, a web service, a windows service, etc. In all of those cases a message box would be inappropriate.

    The right way to handle this is to provide an event that your UI or any other consumer of your business class can subscribe to. Let the UI layer decide whether it will show a message box or not.

    You certainly should also look at some of the logging frameworks out there and probably log this event.