CODEWITHSUNDEEP
c#.net
user786
user786

Reputation: 4364

inner exception in c# .net with simple example

I have been searching for some time but could not find any explanation in simple words. I need to know what is for inner exception in c#.

On msdn, it explains but the example is not quite clear. I need explanation with simple example. thanks

Upvotes: 0

Views: 4728

Answers (4)

Scott Hannen
Scott Hannen

Reputation: 29207

An inner exception is used to wrap an exception in a new exception. Most of the time you don't need to do this. But suppose you have a class that submits an order. That code calls other classes, and somewhere deep inside it throws a NullReferenceException.

If you just try to place an order and you get a NullReferenceException that's rather vague. You might do this:

try
{
    SubmitOrder(order);
}
catch(Exception ex)
{
    throw new OrderSubmitException("An error occurred while placing the order", ex);
}

Now when the order submit fails what you get isn't just a NullReferenceException, it's an OrderSubmitException. When you see that in your log or catch it further up in your application it's easier to tell that it was an exception thrown when placing an order.

But the details, which are really important, are in the InnerException property of your new exception (because you passed that original exception into the constructor.) So you have an OrderSubmitException but you also have the more specific details, like the stacktrace, in the InnerException.

In real life it's not very common that you need to do that. Most of the time when we wrap exceptions like that it's unnecessary. The original exception has its stacktrace and that's good enough.

More often you'll care about the InnerException when inspecting an exception thrown by something else. Often if the exception doesn't contain enough detail there's more in the InnerException, and that might also have its own InnerException.

Upvotes: 2

John Smith
John Smith

Reputation: 131

When an exception X is thrown as a direct result of a previous exception Y. Example:

   public void ThrowInner () 
   {
       throw new MyAppException("ExceptExample inner exception");
   }

   public void CatchInner() 
   {
      try 
      {
          this.ThrowInner();
      }
      catch (Exception e) 
      {
         throw new MyAppException("Error caused by trying ThrowInner.",e);
      }
   }

Upvotes: 1

Wjdavis5
Wjdavis5

Reputation: 4151

Inner exceptions allow you to NEST exceptions.

var exception1 = new Exception("This is the inner exception"); var exception2 = new Exception("This is the outer exception",exception1);

Upvotes: 1

M.S.
M.S.

Reputation: 4423

The InnerException is a property of an exception. When there are series of exceptions, the most current exception can obtain the prior exception in the InnerException property.

See at: http://www.c-sharpcorner.com/uploadfile/puranindia/innerexception-in-C-Sharp/

Upvotes: 3

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