Solved

Class Library Exception Passing To Other Class Library Or Executable?

Posted on 2012-12-22
6
350 Views
Last Modified: 2012-12-27
I want to learn the absolute correct way to pass exceptions from Class Library .dll to other .dll or Executable (Form1). I don't receive the actual .dll exception, instead I receive a general try/catch exception from the Form1 attempt to use the .dll. Help!

[Example Summary]
Click a button on Form1 to clear the local Queue without first specifying the Queue name will cause an exception.
Seems to me the the .dll CreateQueue() exception should 'bubble-up' to Form1.

Does this make sense?

Q1. How do I pass the .dll exception to the .exe (MyForm1)?
Q2. How do I pass the .dll exception to another .dll then to .exe (MyForm1)?

[MyForm1.exe]
public static void ClearQueue()
        {
            msgQueue.QueueName = ""; //intentionally blank for testing purposes
            msgQueue.ClearQueue();
        }


[MyQueueManager.dll] (referenced by MyForm1.exe)
        public static void CreateQueue()
        {
            try
            {
                if (MessageQueue.Exists(_queueName))
                    msgQueue = new MessageQueue(_queueName);
                else
                    msgQueue = MessageQueue.Create(_queueName);
            }
            catch (MessageQueueException ex)
            {
                throw new Exception("MsmqManager.MSMQueue.CreateQueue() Exception: ", ex);
            }
        }

        public static void ClearQueue()
        {
            CreateQueue();

            msgQueue.Purge();
        }
0
Comment
Question by:pointeman
  • 3
  • 3
6 Comments
 
LVL 18

Accepted Solution

by:
Gary Davis earned 500 total points
ID: 38715724
Since your dll is doing a throw, your call to msgQueue will need a try/catch to know the details of the exception being thrown.

Another alternative is to have an Error property within the MessageQueue class and that would have to be set with the error information if an error occurs instead of issuing a throw. Then you will need to test the Error property at various points and act as needed.

Gary Davis
0
 

Author Comment

by:pointeman
ID: 38715761
Q. Do you think the .dll 'Catch' is correct or do you recommend another way?
0
 
LVL 18

Expert Comment

by:Gary Davis
ID: 38716052
The try/catch in the dll looks correct to me.
0
Courses: Start Training Online With Pros, Today

Brush up on the basics or master the advanced techniques required to earn essential industry certifications, with Courses. Enroll in a course and start learning today. Training topics range from Android App Dev to the Xen Virtualization Platform.

 

Author Comment

by:pointeman
ID: 38716084
Q. Do you prefer throw ex; vs my code example?

I've also been working with throw ex.Innexcepion; as well.
0
 
LVL 18

Expert Comment

by:Gary Davis
ID: 38716224
I'm not sure I understand. Your example does issue a throw.
0
 

Author Closing Comment

by:pointeman
ID: 38725618
Thx
0

Featured Post

Live: Real-Time Solutions, Start Here

Receive instant 1:1 support from technology experts, using our real-time conversation and whiteboard interface. Your first 5 minutes are always free.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article is for Object-Oriented Programming (OOP) beginners. An Interface contains declarations of events, indexers, methods and/or properties. Any class which implements the Interface should provide the concrete implementation for each Inter…
Entity Framework is a powerful tool to help you interact with the DataBase but still doesn't help much when we have a Stored Procedure that returns more than one resultset. The solution takes some of out-of-the-box thinking; read on!
This Micro Tutorial will give you a basic overview how to record your screen with Microsoft Expression Encoder. This program is still free and open for the public to download. This will be demonstrated using Microsoft Expression Encoder 4.
Two types of users will appreciate AOMEI Backupper Pro: 1 - Those with PCIe drives (and haven't found cloning software that works on them). 2 - Those who want a fast clone of their boot drive (no re-boots needed) and it can clone your drive wh…

785 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question