Displaying User-Friendly Messages

Article
12/21/2010

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You may want to replace the message in the original exception with a more appropriate, user-friendly message. To do this, you must replace the original exception with another exception that has a more appropriate message associated with it. For example, exceptions that occur in the data access layer of an application can be replaced with an exception of type System.ApplicationException. This uses the message, "The application is unable to process your request at this time." This message is then displayed to the user.

Typical Goals

You want to display a user-friendly message when an exception occurs. Your application has code in its catch blocks similar to the following.

Note

The code does not include implementations of the FormatException and Logger.Log methods. These methods represent typical ways to create and log a formatted exception message.

catch(SomeException e)
{
    string formattedInfo = FormatException(e);
    Logger.Log(formattedInfo);
    throw e;
}

'Usage
Catch e As SomeException
  Dim formattedInfo As String = FormatException(e)
  Logger.Log(formattedInfo)
  Throw e
End Try

Solution

Use either a wrap handler or replace handler to create a new exception with the appropriate message.

QuickStart

For an extended example of how to use the Exception Handling Application Block to display a user-friendly message, see the QuickStart walkthrough, Walkthrough: Notifying the User.