For this he gets punished with a message that tells him little and an empty texbox! This will definitly become a million seller software the world has never seen!!!I tried this method, bt it doesn't enable to me enter "20".. It does what it is supposed to do and that is presents an error when pressing a non-numeric error.
You can use Regular Expression to validate a Textbox to enter number only. I am creating a calculator form, and need to ensure the user enters a numeric only value (no empty values are valid). The user must enter a numeric value only, and if not a message box should appear. Also is it possible to validate both txtboxes at one, or do I need to enter the same code in both textboxes... Wow, man, consider the poor user who just has typed a long accesscode with one typo in it. I don't know much about the error providor, nor the Validating / Validated events. Would this be placed in in some sort of validating procedure?I also wanted to ensure it returned false if the string was empty or null.Try Parse returns true in this case (an empty string does not cause an error when parsing as a number). " ")$" ); static bool Is Numeric( string value ) method twice which of course isn't as efficient, but not everything has to be fully optimized, sometimes convenience is just more important.