Question

I currently handle my exceptions like this:

try {

        }
        catch (ServiceException ex) {
            ModelState.Merge(ex.Errors);
        }
        catch (Exception e) {
            Trace.Write(e);
            ModelState.AddModelError("", "Database access error: " + e.Message);
        }

This works but it’s the same code I repeat many times. What I am looking for is some suggestion on how I could move this into an external function. I don’t necessarily need to move the try block there but at least the other code.

Maybe a function that was passed the Exception and the ModelState (as a reference). Can anyone suggest a clean way that I could code up this function. I’m asking here because almost always someone seems to come up with a solution that I could never have thought of. Thanks Samantha.

Answer 1

You could make a method that takes in an Action, and invokes it in a try/catch block:

private void RunAndHandleExceptions(Action action)
        {
            try
            {
                action.Invoke();
            }
            catch (ServiceException ex)
            {
                ModelState.Merge(ex.Errors);
            }
            catch (Exception e)
            {
                Trace.Write(e);
                ModelState.AddModelError("", "Database access error: " + e.Message);
            }
        }

And call it like this:

RunAndHandleExceptions(new Action(() =>
                {
                    //Do some computing
                }));

EDIT: with a parameter (example, can run in a console program):

private static void ParameterizedTask()
    {
        Task.Factory.StartNew(new Action<object>((y) =>
        {
            Console.WriteLine(y);
        }), 5);
        Thread.Sleep(1500);
    }
//OUTPUT: 5

For more info you can take a look at this thread.