Simple Numeric Edit Control

-->

In our application we needed several edit controls to accept only numbers. One might think to use the Number option on the resource editor, but unfortunately that did not allow us to enter the "-" minus sign. So we needed a different solution.

We looked at CodeGuru to find a simple MaskEdit control. There were several to choose from but unfortunately they all did much more that we needed, and the cursor movement, backspace and delete were not exactly the same as the standard edit control (which was a requirement). With nothing else to do, we (like so many others other there) simply wrote our own.

It was unbelievably simple. Here are the steps we took:

1: Created a new class using class wizard where the base class was CEdit. 2: Added this handler for WM_CHAR

void MaskEdit::OnChar(UINT nChar, UINT nRepCnt, UINT nFlags)
{
 CString Holder =
  "`~!@#$%^&*()_+|=\\qwertyuiop[]asdfghjkl;'zxcvbnm,./QWERTYUIOP{}ASDFGHJKL:/\"
  "ZXCVBNM<>/";

 if(Holder.Find(nChar)!=-1)
  return;

 CEdit::OnChar(nChar, nRepCnt, nFlags);
}

That's it. No it does not check for every possibility in the world, but it does exactly what we needed. It allows us to have an edit control that works exactly like the default, but only allows numbers and the "-" sign. There is probably a more elegant way we could have done this, but this was fast, and it worked.



Comments

Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • Live Event Date: September 23, 2015 @ 1:00 p.m. ET / 10:00 a.m. PT The cloud is not just about a runtime platform for your projects – now, you can do your development in the cloud, too. Check out this upcoming eseminar to learn how the cloud improves your development experience and team collaboration. Join Dana Singleterry, Principal Product Manager for Oracle Dev Tools, as he discusses how to simplify every aspect of the development lifecycle, including requirements gathering, version management, code …

  • Lenovo recommends Windows 8 Pro. "I dropped my laptop getting out of the taxi." This probably sounds familiar to most IT professionals. If your employees are traveling, you know their devices are in for a rough go. Whether it's a trip to the conference room or a convention out of town, any time equipment leaves a user's desk it is at risk of being put into harm's way. Stay connected at all times, whether at the office or on the go, with agile, durable, and flexible devices like the Lenovo® …

Most Popular Programming Stories

More for Developers

RSS Feeds

Thanks for your registration, follow us on our social networks to keep up-to-date