Best practices for catching and re-throwing .NET exceptions

Question

What are the best practices to consider when catching exceptions and re-throwing them? I want to make sure that the Exception object\'s InnerException

Answer 1

A few people actually missed a very important point - 'throw' and 'throw ex' may do the same thing but they don't give you a crucial piece of imformation which is the line where the exception happened.

Consider the following code:

static void Main(string[] args)
{
    try
    {
        TestMe();
    }
    catch (Exception ex)
    {
        string ss = ex.ToString();
    }
}

static void TestMe()
{
    try
    {
        //here's some code that will generate an exception - line #17
    }
    catch (Exception ex)
    {
        //throw new ApplicationException(ex.ToString());
        throw ex; // line# 22
    }
}

When you do either a 'throw' or 'throw ex' you get the stack trace but the line# is going to be #22 so you can't figure out which line exactly was throwing the exception (unless you have only 1 or few lines of code in the try block). To get the expected line #17 in your exception you'll have to throw a new exception with the original exception stack trace.