Exception handling in .net

Question

I have caught an exception and after catching it I have to append the method name so that I should know which method the error came from, and then throw it to another function and save it in database.

try
{
}
catch (Exception ex)
{
    string strError = ex.Message.ToString() + "methodname:getNoOfRecordsForBatchProcess";
    throw strError.ToString();
}

but it gives me error that you can't use string variable to throw exception.the throw exception only use with system exception. is there any way to handle this error.

I dont think its a good way of handling exception. What is your question? — Murali Murugesan, Feb 19 '13 at 10:40
You can't throw a string. You need to wrap it into an `Exception`. — CodesInChaos, Feb 19 '13 at 10:40
You might want to accept answers to your questions. (Simply click on the check mark next to the answer that best answers your questions.) — ispiro, Feb 19 '13 at 10:52
Please accept one of the answers below GetCallingMethodName or getting the stack trace and looking at the top method. For logging, I'd recommend looking into this open source project that I work on which will save you some headaches when it comes to logging: https://github.com/exceptionless/Exceptionless — Blake Niemyjski, Nov 12 '14 at 15:37

score 5 · Answer 1 · answered Feb 19 '13 at 10:39

5

The method name is visible in Exception.StackTrace property too.

By the way you may rely on some other way to recover its name using StackFrame Class, like for example:

        private static string GetCallingMethodName()
        {
            const int iCallDeepness = 2; //DEEPNESS VALUE, MAY CHANGE IT BASED ON YOUR NEEDS
            System.Diagnostics.StackTrace stack = new System.Diagnostics.StackTrace(false);
            System.Diagnostics.StackFrame sframe = stack.GetFrame(iCallDeepness);
            return sframe.GetMethod().Name;
        }

answered Feb 19 '13 at 10:39

Tigran

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I think creating StackTrace is bit expense. But here it is not an issue, cuz already an exception happened. – Murali Murugesan Feb 19 '13 at 10:41
In the below referred response there's the TargetSite Exception property, but the only 100% accurate way to go is using the StackFrame, so +1 – Ricardo Rodrigues Feb 19 '13 at 10:45
This code is DEEPNESS dependent (as I mentioned in answer), so you just call it, in catch block, but it's better to have it in some Log API, so you always sure on what deepness it will be called. – Tigran Feb 19 '13 at 10:45

ispiro · Answer 2 · 2013-02-19T10:53:57.547

1

An answer to your question:

throw new Exception(strError);

(However, as others have said, this might not be the best way to handle this.)

edited Feb 19 '13 at 10:53

answered Feb 19 '13 at 10:47

ispiro

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score 0 · Answer 3 · edited May 23 '17 at 12:27

0

Possible duplicate of How to get the name of the method that caused the exception.

catch (Exception ex)
{
   MethodBase site = ex.TargetSite;
   string methodName = site == null ? null : site.Name;
   ...           
}

edited May 23 '17 at 12:27

Community

1
1

answered Feb 19 '13 at 10:42

Adam K Dean

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score 0 · Answer 4 · answered Feb 19 '13 at 10:44

When catching and rethrowing an exception it's 'recommended' to create a new Exception, with a meaningful error message, and pass the original exception in as the inner exception.

For example:

catch(Exception ex)
{
  const string message = "Some error message.";
  throw new MeaningfulException(message, ex);
}

score 0 · Answer 5 · edited May 23 '17 at 11:56

I would also go for the StackFrame. I'm posting an extension to @Tigran's answer (because you asked for a bit more clarified usage inside the try{...}catch{...} block), so if this is helping you to understand the usage, please accept his answer, not mine:

try
{
    int a = 0;
    var r = 1 / a;
}
catch (Exception ex)
{
    throw new Exception(
        String.Format("{0} Method name: {1}",
            ex.Message,
            GetCallingMethodName()),
        ex);
}

The GetCallingMethodName:

private static string GetCallingMethodName()
{
    const int iCallDeepness = 1; //DEEPNESS VALUE, MAY CHANGE IT BASED ON YOUR NEEDS
    System.Diagnostics.StackTrace stack = new System.Diagnostics.StackTrace(false);
    System.Diagnostics.StackFrame sframe = stack.GetFrame(iCallDeepness);
    return sframe.GetMethod().Name;
}

P.S. @Tigran, I will remove this answer if you consider that it's not needed.

Exception handling in .net

5 Answers5