Question

I`m writing class. Here is one of functions:

public string GetAttribute(string attrName)
{

    try
    {
        return _config.AppSettings.Settings[attrName].Value;
    } catch(Exception e)
    {
        throw new ArgumentException("Element not exists", attrName);
        return null;
    }
}

Then, I am using it in the main form MessageBox.Show(manager.GetAttribute("not_existing_element"));

Visual Studio throws an Exception at line:throw new ArgumentException("Element not exists", attrName);

but, I am want to get an Exception at line MessageBox.Show(manager.GetAttribute("not_existing_element"));

How can I do that?
P.S: Sorry for bad English.

Answer 1

You are misusing exception handling. In your code, if you get (for example) a NullReferenceException, you will catch it and then throw an ArgumentException.

Rewrite your method to not have any exception handling:

public string GetAttribute(string attrName)
{
    return _config.AppSettings.Settings[attrName].Value;
}

This way, you are not resetting the stack trace and swallowing the original exception.

In terms of getting an exception on the calling line – you will never be able to get an exception at a line that isn’t throwing an exception.