How to define behavior that is executed in case of a command-parsing error? [Question]

[Jan Gunnar Carstensen]

On execution, my program takes two arguments it needs to run:

static Task<int> Main(string[] args)
{
   return CommandLineApplication.ExecuteAsync<MyUpdateService>(args);
}

[Argument(0, Description = "Filepath")]
     
private string Filepath { get; }

[Argument(1, Description = "UpdateMode")]

private int Mode { get; }

I want to show a messagebox in case the program is run with too few/ too many arguments, or the arguments don't match the required types (1: string, 2: int).

Since this cannot be achieved by simply wrapping a try/catch-block around it: Can this be done?

[Nate McMaster]

Did you try adding [Required] to both arguments?

[Required, Argument(0, Description = "Filepath")]
private string Filepath { get; }

If that still isn't giving you the error you want, try adding an "OnValidationError" method (example) or using new CommandLineApplication instead (example)

[Jan Gunnar Carstensen]

Thanks for your help.
Eventhough your suggested example seems like the way to go, I have no idea how to implement this in my code.

However, I was able to solve this myself (solution), hence this issue can be closed.