Catching custom exception in c# [closed]

Question

I have created a custom exception class as below

namespace testingEXception
{
    public class CustomException : Exception
    {            
        public CustomException()
        {
        }
        public CustomException(string message)
            : base(message)
        {
        }

        public CustomException(string message, Exception innerException)
            : base(message, innerException)
        {

        }
    }
}

I am throwing an exception from a different project in the same solution like this

namespace ConsoleApplication1
{
    public class testClass
    {
        public void compare()
        {
            if (1 > 0)
            {
                throw new CustomException("Invalid Code");
            }
        }
    }
}

and catching it like this

    namespace testingEXception
{
    class Program
    {
        static void Main(string[] args)
        {
            try
            {
                testClass obj = new testClass();
                obj.compare();

            }
            catch (testingEXception.CustomException ex)
            {
                //throw;
            }
            catch (Exception ex)
            {
               // throw new CustomException(ex.Message);
            }

            Console.ReadKey();
        }
    }
}

The problem is, the exception is not getting caught by the first catch, but instead getting caught by the second catch, over though the type of exception shows CustomException.

Answer 1

You need to provide more detail, the following code outputs "CustomException":

try
{
    throw new CustomException("Invalid code.");
}
catch (CustomException ex)
{
    System.Diagnostics.Trace.WriteLine("CustomException");
    throw;
}
catch (Exception ex)
{
    throw;
}

With the following class:

public class CustomException : Exception
{
    public CustomException()
    {
    }
    public CustomException(string message)
        : base(message)
    {
    }

    public CustomException(string message, Exception innerException)
        : base(message, innerException)
    {

    }
}

Update:

With regard to optimizations and optimizing away a throw: this cannot happen because any particular block of code cannot know whether a caller higher up in the stack could have code to catch CustomException. Throwing an exception is a visible side-effect and there are various guarantees in the CLI to ensure those visible side-effects remain visible.

In addition, try, catch and finally blocks are "protected regions" in CLI-speak. These regions are special in that the operations within the region with "visible" side-effects cannot have their visible side-effects re-ordered. For some more detail, see http://lynk.at/qH8SHk and http://lynk.at/pJcg98