How to determine if an exception is of a particular type

Question

I have a piece of try catch code:

try 
{
    ...
}
catch(Exception ex) 
{
    ModelState.AddModelError(
        \"duplicateInvoiceNumberOrganisation\", \"The com         


        

Answer 1

Not enough rep to comment. In response to @conterio question (in @Davide Piras answer):

is there a catch "when not" syntax?

There is.

catch (Exception e) when (!(e is ArgumentException)) { }