C++ At Work: Form Validation with Regular Expressions In MFC

摘要

I thought I'd use this months column to describe an interesting app I built using the RegexWrap library described in my article "Wrappers: Use Our Man Wrap Library to Get the Best of .NET in Native C++ Code" in this issue. RegexForm is a form validation system for MFC based on regular expressions. This app was my main reason for implementing RegexWrap in the first place. But since many of the details don't relate to regex per se, it makes more sense to describe RegexForm here. As I mentioned in the article, one of the most practical applications of regular expressions is validating user input. Regular expressions make short shrift of validating ZIP codes, phone numbers, credit card numbers—all sorts of real-world information. One regular expression can replace dozens or even hundreds of lines of procedural code. UNIX and Web programming languages like Perl have had regular expressions since Day One, but until the .NET Framework, regular expressions weren't available in Windows* or MFC without a third-party library. So now that .NET provides a complete regular expressions library, why not use it in MFC apps? And with my RegexWrap library described in the main article, you don't even need the Managed Extensions or /clr.